Publications by authors named "Zhengquan Wang"

34 Publications

Exploration of prognostic factors for critical COVID-19 patients using a nomogram model.

Sci Rep 2021 04 14;11(1):8192. Epub 2021 Apr 14.

Medical Quality Management Office, Ningbo Medical Center Lihuili Hospital, Ningbo, Zhejiang, China.

The study aimed to explore the influencing factors on critical coronavirus disease 2019 (COVID-19) patients' prognosis and to construct a nomogram model to predict the mortality risk. We retrospectively analyzed the demographic data and corresponding laboratory biomarkers of 102 critical COVID-19 patients with a residence time ≥ 24 h and divided patients into survival and death groups according to their prognosis. Multiple logistic regression analysis was performed to assess risk factors for critical COVID-19 patients and a nomogram was constructed based on the screened risk factors. Logistic regression analysis showed that advanced age, high peripheral white blood cell count (WBC), low lymphocyte count (L), low platelet count (PLT), and high-sensitivity C-reactive protein (hs-CRP) were associated with critical COVID-19 patients mortality risk (p < 0.05) and these were integrated into the nomogram model. Nomogram analysis showed that the total factor score ranged from 179 to 270 while the corresponding mortality risk ranged from 0.05 to 0.95. Findings from this study suggest advanced age, high WBC, high hs-CRP, low L, and low PLT are risk factors for death in critical COVID-19 patients. The Nomogram model is helpful for timely intervention to reduce mortality in critical COVID-19 patients.
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http://dx.doi.org/10.1038/s41598-021-87373-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8046984PMC
April 2021

Disinfection characteristics of an advanced rotational hydrodynamic cavitation reactor in pilot scale.

Ultrason Sonochem 2021 May 3;73:105543. Epub 2021 Apr 3.

Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Ministry of Education, School of Mechanical Engineering, Shandong University, Jinan 250061, China; National Demonstration Center for Experimental Mechanical Engineering Education, Shandong University, Jinan 250061, China. Electronic address:

Hydrodynamic cavitation is a promising technique for water disinfection. In the present paper, the disinfection characteristics of an advanced hydrodynamic cavitation reactor (ARHCR) in pilot scale were studied. The effects of various flow rates (1.4-2.6 m/h) and rotational speeds (2600-4200 rpm) on the removal of Escherichia coli (E. coli) were revealed and analyzed. The variation regularities of the log reduction and reaction rate constant at various cavitation numbers were established. A disinfection rate of 100% was achieved in only 4 min for 15 L of simulated effluent under 4200 rpm and 1.4 m/h, with energy efficiency at 0.0499 kWh/L. A comprehensive comparison with previously introduced HCRs demonstrates the superior performance of the presented ARHCR system. The morphological changes in E. coli were studied by scanning electron microscopy. The results indicate that the ARHCR can lead to serious cleavage and surface damages to E. coli, which cannot be obtained by conventional HCRs. Finally, a possible damage mechanism of the ARHCR, including both the hydrodynamical and sonochemical effects, was proposed. The findings of the present study can provide strong support to the fundamental understanding and applications of ARHCRs for water disinfection.
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http://dx.doi.org/10.1016/j.ultsonch.2021.105543DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8059091PMC
May 2021

Differences in survival of prostate cancer Gleason 8-10 disease and the establishment of a new Gleason survival grading system.

Cancer Med 2021 01 1;10(1):87-97. Epub 2020 Nov 1.

Shanghai Key Laboratory of Tuberculosis, Clinic and Research Center of Tuberculosis, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China.

Background: Although the latest Gleason grading system in 2014 has distinguished between Gleason 3 + 4 and 4 + 3, Gleason 8 and Gleason 9-10 are remained systemically classified.

Methods: A total of 261,125 patients diagnosed with prostate cancer (PCa) were selected between 2005 and 2015 from the Surveillance, Epidemiology, and End Results (SEER) database. We used propensity score matching to balance clinical variables and then compared overall survival (OS) and cancer-specific survival (CSS) between Gleason score subgroups. We further establish a new Gleason survival grading system based on the hazard ratio (HR) values of each Gleason subgroup. Cox proportional hazards models and Kaplan-Meier curves were used to compare patient survival.

Results: Among PCa patients with Gleason score 8 disease, patients with Gleason 5 + 3 had significantly worse OS and CSS than those with Gleason 3 + 5 (OS: HR = 1.26, p = 0.042; CSS: HR = 1.42, p = 0.005) and 4 + 4 (HR = 1.50 for OS and HR = 1.69 for CSS, p < 0.001 for all). PCa patients with Gleason 5 + 3 and Gleason 4 + 5 may have the similar OS and CSS (reference Gleason score <=6, 5 + 3: OS HR = 2.44, CSS HR = 7.63; 4 + 5: OS HR = 2.40, CSS HR = 8.92; p < 0.001 for all). The new Gleason survival grading system reclassified the grades 4 and 5 of the 2014 updated Gleason grading system into three hierarchical grades, which makes the classification of grades more detailed and accurate.

Conclusion: PCa patients with Gleason 8-10 may have three different survival subgroups, Gleason 3 + 5 and 4 + 4, Gleason 5 + 3 and 4 + 5, and Gleason 5 + 4 and 5 + 5. Our results maximize risk stratification for PCa patients, provide guidance for clinicians to assess their survival and clinical management, and make a recommendation for the next Gleason grading system update.
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http://dx.doi.org/10.1002/cam4.3571DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7826472PMC
January 2021

The impact of previous cancer on overall survival of bladder cancer patients and the establishment of nomogram for overall survival prediction.

Medicine (Baltimore) 2020 Sep;99(38):e22191

Department of Urology Surgery, The People's Hospital of Xuancheng City, Xuanzhou, Xuancheng.

To investigate the role of previous cancer on overall survival in patients with bladder cancer (BCa) and to establish an effective prognostic tool for individualized overall survival prediction.A total of 78,660 patients diagnosed with BCa between 2000 and 2013 were selected from the Surveillance, Epidemiology, and End Results (SEER) database, among which 8915 patients had a history of other cancers. We compared the overall survival between patients with and without previous cancer after propensity score matching and we further established a nomogram for overall survival prediction.Univariate and multivariate Cox analyses were used to determine independent prognostic factors. The calibration curve and concordance index (C-index) were used to assess the accuracy of the nomogram. Cox proportional hazards models and Kaplan-Meier analysis were used to compare survival outcomes.BCa patients with previous cancer had worse overall survival compared with those without previous cancer (HR = 1.37; 95%CI = 1.32-1.42, P < .001). Cancers in lung prior to BCa had the most adverse impact on overall survival (HR = 2.35; 95%CI = 2.10-2.63; P < .001), and the minimal impact was located in prostate (HR = 1.16; 95%CI = 1.10-1.22; P < .001) for male and in gynecological (HR = 1.15; 95%CI = 1.02-1.30; P = .027) for female. The shorter interval time between 2 cancers and the higher stage of the previous cancer development, the higher risk of death. Age, race, sex, marital status, surgery, radiation, grade, stage, type of previous cancer as the independent prognostic factors were selected into the nomogram. The favorable calibration curve and C-index value (0.784, 95%CI = 0.782-0.786) indicated the nomogram could accurately predict the 1-, 3-, and 5-year overall survival rate of BCa patients.Previous cancer has a negative impact on the overall survival of BCa patients and requires more effective clinical management. The nomogram provides accurate survival prediction for BCa patients and might be helpful for clinical treatment selection and follow-up strategy adjustment.
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http://dx.doi.org/10.1097/MD.0000000000022191DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7505356PMC
September 2020

The Effects of Dexmedetomidine Post-Conditioning on Cardiac and Neurological Outcomes After Cardiac Arrest and Resuscitation in Swine.

Shock 2021 Mar;55(3):388-395

Department of Anesthesiology, Yuyao People's Hospital, Medical School of Ningbo University, Ningbo, China.

Introduction: One of the main contents of post-resuscitation care is to alleviate cardiac and neurological damage in cardiac arrest (CA) victims. Recently, dexmedetomidine pre- and post-conditioning have been shown to both effectively protect the heart and brain against regional ischemia reperfusion injury. In this study, we investigated the effects of dexmedetomidine post-conditioning on cardiac and neurological outcomes after CA and resuscitation in swine.

Methods: A total of 28 male domestic swine were randomized into four groups: sham, cardiopulmonary resuscitation (CPR), low-dose dexmedetomidine post-conditioning (LDP), and high-dose dexmedetomidine post-conditioning (HDP). Sham animals underwent the surgical preparation only. The animal model was established by 8 min of CA and then 5 min of CPR. After the animal was successfully resuscitated, a loading dose of 0.25 μg/kg of dexmedetomidine was intravenously injected followed by continuous infusion of 0.25 μg/kg/h for 6 h in the LDP group, and meanwhile a double dose of dexmedetomidine was similarly administered in the HDP group. The same amount of saline was given in the other two groups. All the resuscitated animals were monitored for 6 h and then returned to their cages for an additional 18 h of observation.

Results: After resuscitation, significantly greater cardiac, neurological dysfunction, and injuries were observed in all animals experiencing CA and resuscitation when compared with the sham group. However, the severity of cardiac and neurological damage was significantly milder in the two dexmedetomidine-treated groups than in the CPR group. Dexmedetomidine post-conditioning also significantly decreased post-resuscitation tissue inflammation, oxidative stress, and cell apoptosis and necroptosis in the heart and brain when compared with the CPR group. In addition, these protective effects produced by dexmedetomidine post-conditioning were significantly greater in the HDP group than in the LDP group.

Conclusions: Dexmedetomidine post-conditioning dose-dependently improved post-resuscitation cardiac and neurological outcomes through the inhibition of tissue inflammation, oxidative stress, and cell apoptosis and necroptosis.
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http://dx.doi.org/10.1097/SHK.0000000000001637DOI Listing
March 2021

Limb Ischemic Postconditioning Alleviates Postcardiac Arrest Syndrome through the Inhibition of Mitochondrial Permeability Transition Pore Opening in a Porcine Model.

Biomed Res Int 2020 15;2020:9136097. Epub 2020 Apr 15.

Department of Critical Care Medicine, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.

Objective: Previously, the opening of mitochondrial permeability transition pore (mPTP) was confirmed to play a key role in the pathophysiology of postcardiac arrest syndrome (PCAS). Recently, we demonstrated that limb ischemic postconditioning (LIpostC) alleviated cardiac and cerebral injuries after cardiac arrest and resuscitation. In this study, we investigated whether LIpostC would alleviate the severity of PCAS through inhibiting mPTP opening.

Methods: Twenty-four male domestic pigs weighing 37 ± 2 kg were randomly divided into three groups: control, LIpostC, and LIpostC+atractyloside (Atr, the mPTP opener). Atr (10 mg/kg) was intravenously injected 30 mins prior to the induction of cardiac arrest. The animals were subjected to 10 mins of untreated ventricular fibrillation and 5 mins of cardiopulmonary resuscitation. Coincident with the beginning of cardiopulmonary resuscitation, LIpostC was induced by four cycles of 5 mins of limb ischemia and then 5 mins of reperfusion. The resuscitated animals were monitored for 4 hrs and observed for an additional 68 hrs.

Results: After resuscitation, systemic inflammation and multiple organ injuries were observed in all resuscitated animals. However, postresuscitation systemic inflammation was significantly milder in the LIpostC group than in the control group. Myocardial, lung, and brain injuries after resuscitation were significantly improved in the LIpostC group compared to the control group. Nevertheless, pretreatment with Atr abolished all the protective effects induced by LIpostC.

Conclusion: LIpostC significantly alleviated the severity of PCAS, in which the protective mechanism was associated with the inhibition of mPTP opening.
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http://dx.doi.org/10.1155/2020/9136097DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7182969PMC
February 2021

Prognostic nomograms and Aggtrmmns scoring system for predicting overall survival and cancer-specific survival of patients with kidney cancer.

Cancer Med 2020 04 22;9(8):2710-2722. Epub 2020 Feb 22.

Department of Urology Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, China.

Background: Currently, the prognosis of kidney cancer depends mainly on the pathological grade or tumor stage. Clinicians have few effective tools that can personalize and adequately evaluate the prognosis of kidney cancer patients.

Methods: A total of 70 481 kidney cancer patients were selected from the Surveillance, Epidemiology, and End Results database, among which patients diagnosed in 2005-2011 (n = 42 890) were used to establish nomograms for overall survival (OS) and cancer-specific survival (CSS), and those diagnosed in 2012-2015 (n = 24 591) were used for external validation. Univariate and multivariate Cox analyses were used to determine independent prognostic factors. Concordance index (C-index), receiver operating characteristic curve, and calibration curve were used to evaluate the predictive capacity of the nomograms. We further reduced subgroup classification and used propensity score matching to balance clinical informations, and analyzed the effect of other variables on survival. We established a new kidney cancer prognostic score system based on the effect of all available variables on survival. Cox proportional hazard model and Kaplan-Meier curves were used for survival comparison.

Results: Age, gender, marital status, surgery, grade, T stage, and M stage were included as independent risk factors in the nomograms. The favorable area under the curve (AUC) value (for OS, AUC = 0.812-0.858; and for CSS, AUC = 0.890-0.921), internal (for OS, C-index = 0.776; and for CSS, C-index = 0.856), and external (for OS, C-index = 0.814-0.841; and for CSS, C-index = 0.894-0.904) validation indicated that the proposed nomograms could accurately predict 1-, 3-, and 5-year OS and CSS of kidney cancer patients. The Aggtrmmns prognostic scoring system based on age, gender, race, marital status, grade, TNM stage, and surgery of kidney cancer patients could stage patients more explicitly than the AJCC staging system.

Conclusion: The nomogram and Aggtrmmns scoring system can predict OS and CSS in kidney cancer patients effectively, which may help clinicians personalize prognostic assessments and clinical decisions.
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http://dx.doi.org/10.1002/cam4.2916DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7163106PMC
April 2020

Resolvin D1 Improves Post-Resuscitation Cardiac and Cerebral Outcomes in A Porcine Model of Cardiac Arrest.

Shock 2020 10;54(4):548-554

Department of Critical Care Medicine, The First Hospital of Ninghai, Ningbo, China.

Following global ischemia reperfusion injury triggered by cardiac arrest (CA) and resuscitation, the ensuing cardiac and cerebral damage would result in high mortality and morbidity. Recently, resolvin D1 has been proven to have a protective effect on regional cardiac and cerebral ischemia reperfusion injury. In this study, we investigated the effects of resolvin D1 on cardiac and cerebral outcomes after cardiopulmonary resuscitation (CPR) in a porcine model.Twenty-eight male domestic pigs weighing between 33 and 41 kg were randomly divided into one of the four groups: sham, CPR, low-dose resolvin D1 (LRD), and high-dose resolvin D1 (HRD). Sham animals underwent the surgical preparation only. Other animals were subjected to 8 min of untreated ventricular fibrillation and then 5 min of CPR. At 5 min after resuscitation, resolvin D1 was intravenously administered with the doses of 0.3 and 0.6 μg/kg in the LRD and HRD groups, respectively. The resuscitated animals were monitored for 6 h and observed for an additional 18 h.After resuscitation, myocardial and neurological function were significantly impaired, and their serum levels of injury biomarkers were markedly increased in the CPR, LRD, and HRD groups compared with the sham group. In addition, tissue inflammation and oxidative stress in the heart and brain were observed in the three groups. However, myocardial function was significantly improved and its injury biomarker was significantly decreased starting 3 h after resuscitation in the LRD and HRD groups compared with the CPR group. Similarly, neurological function was significantly better at 24 h post-resuscitation and its injury biomarkers were significantly lower at 6 and 24 h post-resuscitation in the LRD and HRD groups than in the CPR group. In addition, myocardial, cerebral inflammation, and oxidative stress were significantly milder in the two resolvin D1-treated groups. Especially, HRD produced significantly greater post-resuscitation cardiac and cerebral protection compared with the LRD group.In conclusion, resolvin D1 significantly improved post-resuscitation cardiac and cerebral outcomes in a porcine model of CA, in which the protective effects may be in a dose-dependent manner.
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http://dx.doi.org/10.1097/SHK.0000000000001528DOI Listing
October 2020

The effects of an enteral nutrition feeding protocol on critically ill patients: A prospective multi-center, before-after study.

J Crit Care 2020 04 17;56:249-256. Epub 2020 Jan 17.

Department of Emergency Medicine, Wenzhou Central Hospital, Wenzhou, China.

Purpose: The aim of this study was to explore the effects of an enteral nutrition (EN) feeding protocol in critically ill patients.

Methods: This was a prospective multi-center before-after study. We compared energy related and prognostic indicators between the control group (pre-implementation stage) and intervention group (post-implementation stage). The primary endpoint was the percentage of patients receiving EN within 7 days after ICU admission.

Results: 209 patients in the control group and 230 patients in the intervention group were enrolled. The implementation of the EN protocol increased the percentage of target energy reached from day 3 to day 7, and the difference between two groups reached statistical significance in day 6 (P = .01) and day 7 (P = .002). But it had no effects on proportion of patient receiving EN (P = .65) and start time of EN (P = .90). The protocol application might be associated with better hospital survival (89.1% vs 82.8%, P = .055) and reduce the incidence of EN related adverse (P = .004). There was no difference in ICU length of stay, duration of mechanical ventilation and ICU cost.

Conclusion: The implementation of the enteral feeding protocol is associated with improved energy intake and a decreased incidence of enteral nutrition related adverse events for critically ill patients, but it had no statistically beneficial effects on reducing the hospital mortality rate. Trial registration ClinicalTrials.gov, NCT02976155. Registered November 29, 2016- Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT02976155.
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http://dx.doi.org/10.1016/j.jcrc.2020.01.018DOI Listing
April 2020

Evaluation of bacterial and fungal communities during the fermentation of Baixi sufu, a traditional spicy fermented bean curd.

J Sci Food Agric 2020 Mar 28;100(4):1448-1457. Epub 2019 Dec 28.

School of Food Science and Technology, Shanghai Ocean University, Shanghai, China.

Background: Baixi sufu (BS) is a traditional Chinese spicy fermented bean curd manufactured with a natural starter. In this study, the bacterial and fungal communities during BS fermentation were determined by culture and by the culture-independent method of high-throughput sequencing (HTS). Correlation analyses were performed to select the microorganisms potentially contributing to this fermentation.

Results: During the fermentation of BS, 162 bacterial and 97 fungal strains were isolated and identified, and a total of 268 314 bacterial and 287 844 fungal high-quality sequences were analyzed. In general, lactic acid bacteria (LAB), especially Enterococcus and Lactococcus, were dominant in the early stage of fermentation, and spore-forming bacteria, especially Bacillus spp., became the predominant bacteria by the end of fermentation. Geotrichum, Mortierella, and unclassified Ascomycota, were the major fungal populations, which could not be detected in the final product. Correlation analyses indicated that Enterococcus, Bacillus, Geotrichum, and unclassified Ascomycota correlated significantly and positively with amino nitrogen. However, due to the sporulation characteristics of Bacillus, they may have little effect on BS ripening. The presence of Bifidobacterium spp. in sufu is reported for the first time, but the excessive counts of the Bacillus cereus group (>10  CFU g ) indicate a potential hazard to consumers.

Conclusion: The profiles obtained from this study will contribute to the development of autochthonous starter cultures to control BS fermentation, and may lead to the development of novel strategies to shorten the fermentation time of sufu products. © 2019 Society of Chemical Industry.
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http://dx.doi.org/10.1002/jsfa.10151DOI Listing
March 2020

Anatomical structures of fine roots of 91 vascular plant species from four groups in a temperate forest in Northeast China.

PLoS One 2019 1;14(5):e0215126. Epub 2019 May 1.

School of Science, Harbin University, Harbin, China.

Fine roots of plants play an important role in terrestrial ecosystems. There is a close association between the anatomical characteristics and physiological and ecological functions of plants, but we still have a very limited knowledge of anatomical traits. For example, (1) we do not know if herbs and grasses have anatomical patterns similar to those of woody plants, and (2) the variation among different woody plants in the same ecosystem is unclear. In the present study, we analysed the anatomical structures of the fine root systems of various groups of vascular plants (ferns, eudicot herbs, monocots and woody plants) from the same ecosystem (a natural secondary forest on Mao'er Mountain, Heilongjiang, China) to answer the following questions: (1) How does the anatomy of the fine roots change with root order in various plant groups in the same ecosystem? (2) What is the pattern of variation within group? The results show that anatomical traits can be divided into 3 categories: traits that indicate the root capacity to transport resource along the root (stele diameter, xylem cell diameter and xylem cell area); traits that indicate absorptive capacity cortical thickness, (the number of cortical cell layers and the diameter of cortical cells); and traits that are integrated indicators (diameter and the stele to root diameter ratio). The traits indicate the root capacity to transport resource along the root order is generally similar among groups, but absorptive capacity is very different. The shift in function is the main factor influencing the fine root anatomy. Some traits show large variation within groups, but the variations in other traits are small. The traits indicate that the lower-order roots (absorbing roots) in distinct groups are of the first one or two root order in ferns, the first two or three orders in eudicot herbs, the first (only two root orders) or first two orders (more than three root orders) in monocots and the first four or five root orders in woody plants and the other roots are higher-order roots (transport roots). The result will helpful to understand the similarities and differences among groups and the physiological and ecological functions of plant roots.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0215126PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6494041PMC
January 2020

Physicochemical and sensory variables of Maillard reaction products obtained from Takifugu obscurus muscle hydrolysates.

Food Chem 2019 Aug 15;290:40-46. Epub 2019 Mar 15.

Department of Food Science & Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address:

Takifugu obscurus is famous for its delicious taste. In this study, three peptide fractions from Takifugu obscurus muscle hydrolysates were used to evaluate and compare physicochemical and sensory characteristics after Maillard reaction. Maillard reaction products (MRPs) were analyzed by detecting the changes of browning intensity, free amino acids, volatile compounds and taste profile. Results showed that intermediate flavor products in three fractions of MRPs from different molecular weight peptides were much stronger than in control groups. The free amino acids of MRPs from 0.3 to 3.0 kDa and whole fraction showed a similar trend. The contents of volatile compounds (furans, phenols, pyrazines and so on) also increased in the three MRP fractions. The taste characteristics of three fractions showed stronger kokumi effect and umami taste compared to their control groups. To sum up, this investigation lays the groundwork for the development of a flavoring agent from Takifugu obscurus.
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http://dx.doi.org/10.1016/j.foodchem.2019.03.065DOI Listing
August 2019

Small Peptides Isolated from Enzymatic Hydrolyzate of Fermented Soybean Meal Promote Endothelium-Independent Vasorelaxation and ACE Inhibition.

J Agric Food Chem 2017 Dec 7;65(50):10844-10850. Epub 2017 Dec 7.

Shanghai Engineering Research Center of Aquatic-Product Processing & Preservation , Shanghai 201306, China.

Fermentation of soybean is a process in which soy proteins are broken down into small peptides to exert various physiological functions beyond their nutritional value and to improve food source bioactive components responsible for health benefits. Enzymatic hydrolysis could speed up the degradation of proteins during fermentation of soybean, thus resulting in higher peptide production. In the present study, fermented soy meal (fermented with Bacillus subtilis from Douchi) was hydrolyzed by thermolysin, and the water extraction was then separated into four fractions using ultrafiltration membranes. Their vasorelaxation activities were screened, and the most potent fraction was further isolated and purified to obtain four peptides. Briefly, three peptides exerted a dose-dependent vasorelaxation (0.01-4.10 μM) in the phenylephrine preconstricted thoracic aorta ring of Sprague-Dawley rat (relaxation actions were all endothelium-independent), while one peptide induced vasoconstriction. Furthermore, an independent causal relationship between vasorelaxation and angiotensin converting enzyme (ACE) inhibition activities was found.
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http://dx.doi.org/10.1021/acs.jafc.7b05026DOI Listing
December 2017

Determination of Polychlorinated Biphenyls in Fish Tissues from Shanghai Seafood Markets Using a Modified QuEChERS Method.

Anal Sci 2017 ;33(8):973-977

Shanghai Engineering Research Center of Aquatic-Product Processing & Preservation.

Optimized Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) pretreatment methods for determination of six polychlorinated biphenyls (PCBs) residues in fish and aquatic invertebrates samples were investigated. Large volume injection (LVI) coupled gas chromatography tandem mass spectrometry (GC-MS/MS) with selected reaction monitoring (SRM) was used to provide a very sensitive and selective means of analyzing PCBs via internal calibration. Three analytical processes were validated and compared, and the florisil Celite545 pretreatment method was selected. Performance characteristics, such as linearity, limit of detection (LOD), limit of quantization (LOQ), recovery and precision (relative standard deviation, RSD) were studied. The method was applied to 233 samples obtained from local markets, which was useful and thus suggested that the method could serve as a screening model for PCB residues analysis.
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http://dx.doi.org/10.2116/analsci.33.973DOI Listing
August 2018

Development of an Analytical Method Based on Temperature Controlled Solid-Liquid Extraction Using an Ionic Liquid as Solid Solvent.

Molecules 2015 Dec 10;20(12):22137-45. Epub 2015 Dec 10.

School of Chemical and Biological Science, Quanzhou Normal University, Quanzhou, 362000, China.

At the present paper, an analytical method based on temperature controlled solid-liquid extraction (TC-SLE) utilizing a synthesized ionic liquid, (N-butylpyridinium hexafluorophosphate, [BPy]PF₆), as solid solvent and phenanthroline (PT) as an extractant was developed to determine micro levels of Fe(2+) in tea by PT spectrophotometry. TC-SLE was carried out in two continuous steps: Fe(2+) can be completely extracted by PT-[BPy]PF₆ or back-extracted at 80 °C and the two phases were separated automatically by cooling to room temperature. Fe(2+), after back-extraction, needs 2 mol/L HNO₃ as stripping agent and the whole process was determined by PT spectrophotometry at room temperature. The extracted species was neutral Fe(PT)mCl₂ (m = 1) according to slope analysis in the Fe(2+)-[BPy]PF₆-PT TC-SLE system. The calibration curve was Y = 0.20856X - 0.000775 (correlation coefficient = 0.99991). The linear calibration range was 0.10-4.50 μg/mL and the limit of detection for Fe(2+) is 7.0 × 10(-2) μg/mL. In this method, the contents of Fe(2+) in Tieguanyin tea were determined with RSDs (n = 5) 3.05% and recoveries in range of 90.6%-108.6%.
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http://dx.doi.org/10.3390/molecules201219842DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6332100PMC
December 2015

Root tip morphology, anatomy, chemistry and potential hydraulic conductivity vary with soil depth in three temperate hardwood species.

Tree Physiol 2016 Jan 30;36(1):99-108. Epub 2015 Sep 30.

School of Forestry, Northeast Forestry University, Harbin 150040, China

Root traits in morphology, chemistry and anatomy are important to root physiological functions, but the differences between shallow and deep roots have rarely been studied in woody plants. Here, we selected three temperate hardwood species, Juglans mandshurica Maxim., Fraxinus mandschurica Rupr. and Phellodendron amurense Rupr., in plantations in northeastern China and measured morphological, anatomical and chemical traits of root tips (i.e., the first-order roots) at surface (0-10 cm) and subsurface (20-30 cm) soil layers. The objectives of this study were to identify how those traits changed with soil depth and to reveal potential functional differences. The results showed that root diameters in deep root tips were greater in J. mandshurica and F. mandschurica, but smaller in P. amurense. However, root stele diameter and the ratio of stele to root diameter in the subsurface layer were consistently greater in all three species, which may enhance their abilities to penetrate into soil. All deep roots exhibited lower tissue nitrogen concentration and respiration rate, which were possibly caused by lower nutrient availability in the subsurface soil layer. Significant differences between shallow and deep roots were observed in xylem structure, with deep roots having thicker stele, wider maximum conduit and greater number of conduits per stele. Compared with shallow roots, the theoretical hydraulic conductivities in deep roots were enhanced by 133% (J. mandshurica), 78% (F. mandschurica) and 217% (P. amurense), respectively, indicating higher efficiency of transportation. Our results suggest that trees' root tip anatomical structure and physiological activity vary substantially with soil environment.
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http://dx.doi.org/10.1093/treephys/tpv094DOI Listing
January 2016

Whole-tree dynamics of non-structural carbohydrate and nitrogen pools across different seasons and in response to girdling in two temperate trees.

Oecologia 2015 Feb 19;177(2):333-44. Epub 2014 Dec 19.

Key Laboratory of Horticultural Plant Biology, Huazhong Agricultural University, Ministry of Education of China, Wuhan, 430070, China.

Despite extensive research on the seasonal dynamics of non-structural carbohydrate (NSC) and nitrogen (N) concentrations, the size and relative contributions of NSC and N pools across different tree organs are not well understood. We have measured the changes in NSC and N concentrations in leaves, branches, stems and all root branch orders at monthly intervals in control and girdled trees of larch (Larix gmelinii) and ash (Fraxinus mandshurica). The biomass of each plant compartment was also determined to calculate the size of the NSC and N pools. In both species, 13-37% of the NSC and N pools were mobilized at the beginning of the growing season. Among the mobilized pools, stems and non-absorptive roots (branch orders 4-9) acted as the largest NSC sources in larch and ash, respectively, while branches served as the largest N source in both species. After stem girdling, 22 and 50% of the root NSC stores in larch and ash, respectively, were mobilized to maintain root activities during the growing season. Tree mortality was observed 1 year after girdling, at which time there was still an abundant NSC pool in the roots. We conclude that (1) different storage organs differ in their contribution to new tissue growth at the beginning of the growing season and that those storage organs holding higher fractions of the NSC or N pool are not necessarily those which mobilize more NSC or N; (2) tree growth may not be limited by carbon (C) availability; (3) C storage in non-absorptive roots plays an important role in maintaining tree survival after the termination of photosynthate flow from aboveground sources.
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http://dx.doi.org/10.1007/s00442-014-3186-1DOI Listing
February 2015

Root diameter variations explained by anatomy and phylogeny of 50 tropical and temperate tree species.

Tree Physiol 2014 Apr 2;34(4):415-25. Epub 2014 Apr 2.

School of Forestry, Northeast Forestry University, Harbin 150040, China.

Root diameter, a critical indicator of root physiological function, varies greatly among tree species, but the underlying mechanism of this high variability is unclear. Here, we sampled 50 tree species across tropical and temperate zones in China, and measured root morphological and anatomical traits along the first five branch orders in each species. Our objectives were (i) to reveal the relationships between root diameter, cortical thickness and stele diameter among tree species in tropical and temperate forests, and (ii) to investigate the relationship of both root morphological and anatomical traits with divergence time during species radiation. The results showed that root diameter was strongly affected by cortical thickness but less by stele diameter in both tropical and temperate species. Changes in cortical thickness explained over 90% of variation in root diameter for the first order, and ∼74-87% for the second and third orders. Thicker roots displayed greater cortical thickness and more cortical cell layers than thinner roots. Phylogenetic analysis demonstrated that root diameter, cortical thickness and number of cortical cell layers significantly correlated with divergence time at the family level, showing similar variation trends in geological time. The results also suggested that trees tend to decrease their root cortical thickness rather than stele diameter during species radiation. The close linkage of variations in root morphology and anatomy to phylogeny as demonstrated by the data from the 50 tree species should provide some insights into the mechanism of root diameter variability among tree species.
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http://dx.doi.org/10.1093/treephys/tpu019DOI Listing
April 2014

Relationships between root respiration rate and root morphology, chemistry and anatomy in Larix gmelinii and Fraxinus mandshurica.

Tree Physiol 2013 Jun;33(6):579-89

Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, PR China.

Tree roots are highly heterogeneous in form and function. Previous studies revealed that fine root respiration was related to root morphology, tissue nitrogen (N) concentration and temperature, and varied with both soil depth and season. The underlying mechanisms governing the relationship between root respiration and root morphology, chemistry and anatomy along the root branch order have not been addressed. Here, we examined these relationships of the first- to fifth-order roots for near surface roots (0-10 cm) of 22-year-old larch (Larix gmelinii L.) and ash (Fraxinus mandshurica L.) plantations. Root respiration rate at 18 °C was measured by gas phase O2 electrodes across the first five branching order roots (the distal roots numbered as first order) at three times of the year. Root parameters of root diameter, specific root length (SRL), tissue N concentration, total non-structural carbohydrates (starch and soluble sugar) concentration (TNC), cortical thickness and stele diameter were also measured concurrently. With increasing root order, root diameter, TNC and the ratio of root TNC to tissue N concentration increased, while the SRL, tissue N concentration and cortical proportion decreased. Root respiration rate also monotonically decreased with increasing root order in both species. Cortical tissue (including exodermis, cortical parenchyma and endodermis) was present in the first three order roots, and cross sections of the cortex for the first-order root accounted for 68% (larch) and 86% (ash) of the total cross section of the root. Root respiration was closely related to root traits such as diameter, SRL, tissue N concentration, root TNC : tissue N ratio and stele-to-root diameter proportion among the first five orders, which explained up to 81-94% of variation in the rate of root respiration for larch and up to 83-93% for ash. These results suggest that the systematic variations of root respiration rate within tree fine root system are possibly due to the changes of tissue N concentration and anatomical structure along root branch orders in both tree species, which provide deeper understanding in the mechanism of how root traits affect root respiration in woody plants.
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http://dx.doi.org/10.1093/treephys/tpt040DOI Listing
June 2013

Effect of nitrogen fertilizer, root branch order and temperature on respiration and tissue N concentration of fine roots in Larix gmelinii and Fraxinus mandshurica.

Tree Physiol 2011 Jul;31(7):718-26

Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130012, PR China.

Root respiration is closely related to root morphology, yet it is unclear precisely how to distinguish respiration-related root physiological functions within the branching fine root system. Root respiration and tissue N concentration were examined for different N fertilization treatments, sampling dates, branch orders and temperatures of larch (Larix gmelinii L.) and ash (Fraxinus mandshurica L.) using the excised roots method. The results showed that N fertilization enhanced both root respiration and tissue N concentration for all five branch orders. The greatest increases in average root respiration for N fertilization treatment were 13.30% in larch and 18.25% in ash at 6°C. However, N fertilization did not change the seasonal dynamics of root respiration. Both root respiration and root tissue N concentration decreased with increase in root branch order. First-order (finest) roots exhibited the highest respiration rates and tissue N concentrations out of the five root branch orders examined. There was a highly significant linear relationship between fine root N concentration and root respiration rate. Root N concentration explained >60% of the variation in respiration rate at any given combination of root order and temperature. Root respiration showed a classical exponential relationship with temperature, with the Q(10) for root respiration in roots of different branching orders ranging from 1.62 to 2.20. The variation in root respiration by order illustrates that first-order roots are more metabolically active, suggesting that roots at different branch order positions have different physiological functions. The highly significant relationship between root respiration at different branch orders and root tissue N concentration suggests that root tissue N concentration may be used as a surrogate for root respiration, simplifying future research into the C dynamics of rooting systems.
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http://dx.doi.org/10.1093/treephys/tpr057DOI Listing
July 2011

Trp-His, a vasorelaxant di-peptide, can inhibit extracellular Ca2+ entry to rat vascular smooth muscle cells through blockade of dihydropyridine-like L-type Ca2+ channels.

Peptides 2010 Nov 3;31(11):2060-6. Epub 2010 Aug 3.

Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School of Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.

Our previous findings regarding the biological activities of small peptides revealed that a di-peptide, Trp-His (WH), could play a role in the prevention of vascular lesions, including cell proliferation and atherosclerosis. Its vasoprotective effects could be associated with suppression of the vasocontraction signaling cascade, but the underlying mechanism(s) remains obscure. In this study, we attempted to elucidate the vasoprotective mechanism of WH, in opposing the proliferation of rat vascular smooth muscle cells (VSMCs). In VSMCs from 8 week-old male Wistar rat thoracic aortae, WH evoked a significant dose-dependent anti-proliferation effect, without cytotoxicity. In mitogen-stimulated cell experiments, 300 μM WH inhibited cytosolic Ca(2+) elevation in VSMCs induced by 10 μM angiotensin II (Ang II). Furthermore, WH suppressed extracellular Ca(2+) entry into CaCl(2)-stimulated VSMCs. The biological capacity of WH as an intracellular Ca(2+) ([Ca(2+)](i)) suppressor was also proven when 50 μM Bay K8644 was used to enhance Ca(2+) entry via a voltage-dependent l-type Ca(2+) channel (VDCC) and 300 μM WH elicited a 23% reduction in [Ca(2+)](i). The absence of a reduction of the [Ca(2+)](i) by the mixture of tryptophan and histidine revealed the importance of the peptide backbone in the [Ca(2+)](i) reduction effect. Furthermore, the WH-induced [Ca(2+)](i) reduction was abolished by verapamil, but not by nifedipine, indicating that WH likely binds to an extracellular site of the VDCC at a site similar to that of the dihydropyridine type-Ca(2+) channel blockers.
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http://dx.doi.org/10.1016/j.peptides.2010.07.013DOI Listing
November 2010

His-Arg-Trp potently attenuates contracted tension of thoracic aorta of Sprague-Dawley rats through the suppression of extracellular Ca2+ influx.

Peptides 2009 Aug 22;30(8):1502-7. Epub 2009 May 22.

Faculty of Agriculture, Graduate School of Kyushu University, Fukuoka, 812-8581, Japan.

In the present study, we primarily attempted to identify di- and tri-peptides showing potent vasodilation in 1.0 microM phenylephrine-contracted thoracic aortas of Sprague-Dawley rats. Synthetic 15 Trp-His (WH) skeleton analogues were used for rat aorta ring's force measurements, since WH was found to be a vasoactive di-peptide so far. Among the synthesized peptides consisted of both His and Trp amino acid residues, His-Arg-Trp (HRW) was found to evoke the most potent vasodilation with an EC50 value of 1.2+/-0.08 mM in an endothelium-independent manner, while no effect was evoked by a mixture of individual amino acids. In addition to the structure of tri-peptides-activity relationship, chemically modified HRW analogues, i.e., 1- or 3-methyl-His-Arg-Trp and His-citrulline-Trp demonstrated the structural importance of tri-peptide to evoke the vasoactivity as following factors: (1) Neutral imidazole and indole groups from His and Trp residues at N- and C-terminals, respectively and (2) basic amino acids at the middle position. In mitogen (10 microM angiotensin II or 50 microM Bay K8644)-stimulated vascular smooth muscle cells, vasoactive HRW (100 microM) caused significant [Ca(2+)](i) reduction to an extent of >30%. Thus, our results suggest that HRW caused vasodilation action via an endothelium-independent mechanism which probably involves the suppression of extracellular Ca2+ influx through voltage-gated l-type Ca2+ channel.
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http://dx.doi.org/10.1016/j.peptides.2009.05.012DOI Listing
August 2009

Anatomical traits associated with absorption and mycorrhizal colonization are linked to root branch order in twenty-three Chinese temperate tree species.

New Phytol 2008 22;180(3):673-683. Epub 2008 Jul 22.

School of Forestry, Northeast Forestry University, Harbin 150040, China.

* Different portions of tree root systems play distinct functional roles, yet precisely how to distinguish roots of different functions within the branching fine-root system is unclear. * Here, anatomy and mycorrhizal colonization was examined by branch order in 23 Chinese temperate tree species of both angiosperms and gymnosperms forming ectomycorrhizal and arbuscular-mycorrhizal associations. * Different branch orders showed marked differences in anatomy. First-order roots exhibited primary development with an intact cortex, a high mycorrhizal colonization rate and a low stele proportion, thus serving absorptive functions. Second and third orders had both primary and secondary development. Fourth and higher orders showed mostly secondary development with no cortex or mycorrhizal colonization, and thus have limited role in absorption. Based on anatomical traits, it was estimated that c. 75% of the fine-root length was absorptive, and 68% was mycorrhizal, averaged across species. * These results showed that: order predicted differences in root anatomy in a relatively consistent manner across species; anatomical traits associated with absorption and mycorrhizal colonization occurred mainly in the first three orders; the single diameter class approach may have overestimated absorptive root length by 25% in temperate forests.
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http://dx.doi.org/10.1111/j.1469-8137.2008.02573.xDOI Listing
March 2009

[Effects of cutting intensity on spatial heterogeneity of topsoil temperature in secondary forest in Maoershan region of Heilongjian Province].

Ying Yong Sheng Tai Xue Bao 2006 Dec;17(12):2248-54

College of Forestry, Northeast Forestry University, Harbin 150040, China.

This paper studied the effects of different cutting intensity on the spatial heterogeneity of topsoil (3 - 5 cm) temperature in the secondary forest in Maoershan region of Heilongjiang Province. Three treatments were installed, i.e., no cutting (treatment A), 50% of randomly cutting (treatment B), and clear cutting (treatment C). Based on the requirements of geostatistic analysis, there were 160, 154 and 154 sampling points with a spatial distance of 0.5 - 56 m in the treatments A, B and C, respectively. Topsoil temperature was measured by thermometer in spring and summer during the two years after cutting, and the spatial heterogeneity of the temperature was analyzed by semivariogram and Kriging arithmetic. The results showed that after cutting, the mean value of topsoil temperature had an increase of 0.6 - 4.2 degrees C (P < 0.001), and correlated positively with cutting intensity. The spatial heterogeneity and variation degree of topsoil temperature also increased with the increasing intensity of cutting. As for the small scale spatial heterogeneity of topsoil temperature, it was also increased after cutting, but the scale was mainly within the range of < 20 m and the composition of spatial heterogeneity was slightly affected. The comparison of Kriging maps suggested that in treatments B and C, the spatial pattern strength of topsoil temperature was enhanced, and the difference between treatments B and C and treatment A was larger in spring than in summer. In treatments B and C, topsoil temperature fluctuated and had similar distribution patterns in the same seasons; while in treatment A, the temperature had a relatively even distribution within the year.
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December 2006

[Root decomposition and nutrient release of Fraxinus manshurica and Larix gmelinli plantations].

Ying Yong Sheng Tai Xue Bao 2006 Aug;17(8):1370-6

School of Forestry, Northeast Forestry University, Harbin 150040, China.

A two-year buried bag experiment with different sizes of Fraxinus mandshurica and Larix gmelinii roots showed that the coarse (5 to approximately 10 mm), medium (2 to approximately 5 mm) and fine ( <2 mm) roots of F. mandshurica had an annual decomposition coefficient of 0.3649, 0.4381 and 0.2720, while those of L. gmelinii had the coefficient of 0.1967, 0.1955 and 0.2464, respectively. During root decomposition, large amounts of carbon and nutrients released. After buried into soil for 150 days, more than 90% of soluble sugar in all sizes of the two species roots was released, and about 40%, 71% and 95% of potassium was released from the coarse and medium, and fine roots of F. mandshurica, and all sizes of L. gmelinii roots, respectively. In the second year of the experiment, about 50% of nitrogen and 40% of phosphorus were released from the coarse and medium roots of the two species, and 60% of nitrogen and phosphorus were released from their fine roots. In the study of forest ecosystem's carbon and nutrient cycles, root decomposition shouldn't be ignored.
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August 2006

[Application of minirhizotron in fine root studies].

Ying Yong Sheng Tai Xue Bao 2006 Apr;17(4):715-9

College of Forestry, Northeast Forestry University, Harbin 150040, China.

Due to the production, death, and decomposition of fine root, its turnover plays an important role in carbon allocation and nutrient cycling in terrestrial ecosystems. Some methods such as sequential root coring, compartmental flow model, and ingrowth core have been widely used in collecting root biomass data and estimating fine root turnover, but failed in monitoring the dynamics of fine root due to its simultaneous production and death. Minirhizotron is a nondestructive in situ method for studying the dynamics of fine root, which allows the simultaneous measurement of fine root growth and mortality. This paper reviewed the application of minirhizotron in fine root studies, with the focus on minirhizotron tube installation, image collection, data extraction, and calculation parameters. In a case study, the total fine root length, fine root length density per unit volume, fine root length density per unit area, fine root biomass density, and fine root production and mortality of Fraxinus mandshurica and Larix gmelini were calculated, and the results showed that minirhizotron method was feasible in studying the processes of fine root development, eclipse, death, and decomposition. The factors affecting fine root measurement and its precision mainly included the quality and quantity of tube installation, sampling interval and quantity, and analysis technique of images, etc. Soil texture, tube material, and disturbance of light on root were also the factors affecting the precision of the method. How to improve the measurement precision of minirhizotron would be the critical problem in future study.
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April 2006

[Distribution patterns of Fraxinus mandshurica root biomass, specific root length and root length density].

Ying Yong Sheng Tai Xue Bao 2006 Jan;17(1):1-4

College of Forestry, Northeast Forestry University, Harbin, China.

Employing soil core method, an investigation in Maoershan Experiment Station was made on the root biomass, specific root length (SRL), and root length density (RLD) of Fraxinus mandshurica plantation (17 yr) within a growth season in stand level. The results showed that the total root biomass was 1,637 g x m(-2), in which, living biomass accounted for 85%, and necrotic biomass was 15%. In the living biomass, coarse roots (5 approximately 30 mm in diameter) had the highest percentage (69.95 %), followed by fine roots (< 1 mm in diameter) (13.53 %), medium roots (2 approximately 5 mm in diameter) (7.21%), and small roots (1 approximately 2 mm in diameter) (9.31%). Among the four diameter classes, fine roots had a higher SRL (32.20 m x g(-1)), while coarse roots had a lower one (0.08 m x g(-1)). The total RLD in living biomass was 6,602.54 m x m(-2) in stand level, among which, fine root accounted for 92.43%, and the others was less than 8%. Fine root biomass and RLD had a positive correlation with soil available nitrogen, while no significant correlation was found between SRL and soil available nitrogen.
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January 2006

[Effects of nitrogen stress on nutrient uptake by Fraxinus mandshurica seedlings and their biomass distribution].

Ying Yong Sheng Tai Xue Bao 2004 Nov;15(11):2034-8

School of Forest Resource and Environment, Northeast Forestry University, Harbin 150040, China.

Under environmental stresses, trees often change their morphological and physiological components to acquire the most limited resources. In northeastern forest region of China, the decomposition and mineralization of litters occur slowly due to low temperature, which often results in forest trees suffering from nutritional stress. With pot culture in greenhouse, this paper studied the effects of nitrogen stress on the physiological and morphological components of Fraxinus mandshurica seedlings. The results showed that under N stress, the net uptake rate of nitrogen and phosphate by the seedlings decreased, while their nitrogen and phosphate use efficiency were higher than those of the seedlings supplied with 8 mmol x L(-1) or 16 mmol x L(-1) of nitrogen during the early growth stage. When suffering from N stress, the leaf mass ratio of the seedlings reduced, with specific leaf area and root mass ratio increased. The relative growth rate increased with the increasing N concentrations supplied to the seedlings during the whole growth period. Under N stress, the net assimilation rate decreased, which resulted in the decrease of total biomass, and the root/shoot ratio was significantly higher than that of the seedlings supplied with 8 mmol x L(-1) or 16 mmol x L(-1) of nitrogen during the early growth stage. There was no significant difference during the late growth stage.
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November 2004

[Effect of different nitrogen supply on Fraxinus mandshurica seedling's biomass, N partitioning and their seasonal variation].

Ying Yong Sheng Tai Xue Bao 2004 Sep;15(9):1497-501

School of Forestry, Northeast Forestry University, Harbin 150040, China.

Nitrogen is one of the most important limiting nutrients for tree growth in temperature forest ecosystems. In this paper, the effects of nitrogen treatments on nitrogen partition and biomass allocation in roots and leaves of one-year-old Fraxinus mandshurica seedlings were studied during a five-month period. The plants were sand-cultured in pots supplied with various concentrations of N (1, 4, 8, 16 mmol x L(-1)). The results suggested that N supply could significantly increase the N concentration in roots and leaves. In the initial (June) and middle growth stage (July and August), the N concentration in leaves was over 9.40, 9.55 and 4.21 mg x g(-1) respectively, which was higher than that in roots, but in the latter growth stage (September), it was lower than that in roots. From June to September, the N content of whole plant increased markedly, and was 4 times more in September than in June. The N content in Ash seedlings varied with N supply. It increased by 5.5 times in 16 mmol x L(-1) N treatment, in comparing with 1 mmol x L(-1) N treatment in September. The N allocation also varied in leaf, stem, and root. The proportion of N allocation in leaf was the highest in June (43% in average), and the lowest in September (9% in average). The proportion of N allocation to root increased with plant growth, which was the highest in September (81% in average). Regardless N treatments and tree growth stages, the proportion of N allocation to root was the highest, followed by to leaf, and the lowest was to stem. These results provided the theoretical foundation for the further studies of nitrogen absorption and carbon allocation mechanism in root system of Manchurian ash.
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September 2004

[A preliminary study on wood-inhabiting fungi on charred wood in Daxinganling forest areas].

Ying Yong Sheng Tai Xue Bao 2004 Oct;15(10):1781-4

Northeast Forestry University, Harbin, China.

Study on wood-inhabiting fungi is one of the active fields of mycology during past 30 years in China, and the study mostly focused on natural forest without fire disturbing. Forest fire changes forest ecology dramatically, and the fungi on charred wood are different from those in nature forests without fires. In this paper, we focused on the wood-inhabiting fungi growing on charred wood in Daxinganling forest areas. Seventeen species were reported: Antrodia sp., Antrodia rantha, Ceriporiopsis mucida, Diplomitoporus lindbladii, Gloeophyllum carbonarium, Gloeophyllum sepiarium, Gloeoporus taricola, Laurilia sulcata, Oligoporus sericeomollis, Phellinus igniarius, Postia caesia, Postia leucomallella, Postia tephroleuca, Schizopora flavipora, Skeletocutis ochroalba, Skeletocutis vulgaris, and Trichaptum fuscoviolaceum. Among them, eight species caused brown rot, and nine species caused white rot. Based on our field studies, eight species were pioneer fungi in charred wood, four species were common one, and three species were rare or threatened in the studied area. Setting up nature reserve should be the best way to protect the rare or threatened species of wood-inhabiting fungi.
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October 2004