Publications by authors named "Jianbing Guo"

8 Publications

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Determinants of smallholder farmers' choice on mulch film thickness in rural China.

Environ Sci Pollut Res Int 2021 Apr 18. Epub 2021 Apr 18.

Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China.

Agricultural mulch film pollution has become a prevailing concern. Studies have shown that the thickness of mulch film is a key factor affecting mulch film recycling, but research about farmers' choice on mulch film thickness is lacking. Based on survey data from 2025 households in five Chinese provinces in 2018, the Heckman two-stage model was used to analyze the influencing factors of farmers' choice on mulch film thicknesses. Mulch film had been used by 21.98% of the sample households, and 41.47% of the used mulch film did not meet the national thickness standard. The econometric results showed that farmers' product cognition and market factors were the two most important factors, and there was a significant negative correlation with the choice of film thickness. In addition, the choice of mulch film with different thicknesses was affected by household characteristics, subjective norms, and farmland property rights. Strengthening and stabilizing farmland property rights is a long-term mechanism to promote farmers to choose thicker mulch film. In addition to strengthening the production and sale of substandard film supervision, farmers' choice of film thickness should be included in village regulations and other rural grass-roots governance systems, especially in the mechanism design between agricultural farmland protective subsidies and the prevention of mulch film pollution, rather than just considering the recycling itself.
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http://dx.doi.org/10.1007/s11356-021-13866-xDOI Listing
April 2021

Red and processed meat consumption and cancer outcomes: Umbrella review.

Food Chem 2021 Mar 27;356:129697. Epub 2021 Mar 27.

Department of Urology/Institute of Urology, West China Hospital, Sichuan University, Chengdu 610041, China. Electronic address:

The purpose of this umbrella review was to evaluate the quality of evidence, validity and biases of the associations between red and processed meat consumption and multiple cancer outcomes according to existing systematic reviews and meta-analyses. The umbrella review identified 72 meta-analyses with 20 unique outcomes for red meat and 19 unique outcomes for processed meat. Red meat consumption was associated with increased risk of overall cancer mortality, non-Hodgkin lymphoma (NHL), bladder, breast, colorectal, endometrial, esophageal, gastric, lung and nasopharyngeal cancer. Processed meat consumption might increase the risk of overall cancer mortality, NHL, bladder, breast, colorectal, esophageal, gastric, nasopharyngeal, oral cavity and oropharynx and prostate cancer. Dose-response analyses revealed that 100 g/d increment of red meat and 50 g/d increment of processed meat consumption were associated with 11%-51% and 8%-72% higher risk of multiple cancer outcomes, respectively, and seemed to be not correlated with any benefit.
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http://dx.doi.org/10.1016/j.foodchem.2021.129697DOI Listing
March 2021

Triply Biobased Thermoplastic Composites of Polylactide/Succinylated Lignin/Epoxidized Soybean Oil.

Polymers (Basel) 2020 Mar 10;12(3). Epub 2020 Mar 10.

Department of Polymer Material and Engineering, College of Materials and Metallurgy, Guizhou University, Guiyang 550025, China.

Soybean oil is beneficial to improve the compatibility between polylactide (PLA) and succinylated lignin (SAL), which leads to the preparation of a host of biobased composites containing PLA, SAL, and epoxidized soybean oil (ESO). The introduction of SAL and ESO enables the relatively homogeneous morphology and slightly better miscibility obtained from triply PLA/SAL/ESO composites after dynamic vulcanization compared with unmodified PLA. The rigidity of the composites is found to decline gradually due to the addition of flexible molecular chains. According to the reaction between SAL and ESO, the of PLA/SAL/ESO composites is susceptible to the movement of flexible molecular chains. The rheological behaviors of PLA/SAL/ESO under different conditions, i.e., temperature and frequency, exhibit a competition between viscidity and elasticity. The thermal stability of the composites displays a slight decrease due to the degradation of SAL and then the deterioration of ESO. The elongation at break and notched impact strength of the composites with augmentation of ESO increase by 12% and 0.5 kJ/m, respectively. The triply biobased PLA/SAL/ESO composite is thus deemed as a bio-renewable and environmentally friendly product that may find vast applications.
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http://dx.doi.org/10.3390/polym12030632DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7182957PMC
March 2020

The Influence of Compatibility on the Structure and Properties of PLA/Lignin Biocomposites by Chemical Modification.

Polymers (Basel) 2019 Dec 31;12(1). Epub 2019 Dec 31.

Department of Polymer Material and Engineering, College of Materials and Metallurgy, Guizhou University, Guiyang 550025, China.

Lignin, a natural amorphous three-dimensional aromatic polymer, is investigated as an appropriate filler for biocomposites. The chemical modification of firsthand lignin is an effective pathway to accomplish acetoacetate functional groups replacing polar hydroxyl (-OH) groups, which capacitates lignin to possess better miscibility with poly(lactic acid) (PLA), compared with acidified lignin (Ac-lignin) and butyric lignin (By-lignin), for the sake of blending with poly(lactic acid) (PLA) to constitute a new biopolymer based composites. Generally speaking, the characterization of all PLA composites has been performed taking advantage of Fourier transform infrared (FTIR), scanning electron microscopy (SEM), dynamic Mechanical analysis (DMA), differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), rheological analysis, and tensile test. Visibly, it is significant to highlight that the existence of acetoacetate functional groups enhances the miscibility, interfacial compatibility, and interface interaction between acetoacetate lignin (At-lignin) and PLA. Identical conclusions were obtained in this study where PLA/At-lignin biocomposites furthest maintain the tensile strength of pure PLA.
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http://dx.doi.org/10.3390/polym12010056DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7023527PMC
December 2019

Clinical characteristics of testicular seminoma in individuals in West China: a 10-year follow-up study.

Cancer Manag Res 2019 14;11:7639-7645. Epub 2019 Aug 14.

Department of Urology/Institute of Urology, West China Hospital, Sichuan University, Chengdu 610041, People's Republic of China.

Objective: To assess the clinical characteristics of testicular seminoma (TS).

Patients And Methods: A testicular cancer (TC) survey was conducted by the Department of Urology, West China Hospital, between 2008 and 2018. Tumors were classified according to the NCCN criteria such as age, tumor size, tumor marker levels, histopathology, clinical stage, initial treatment, follow-up, and clinical outcomes, were obtained from the database of our center.

Results: Among 155 registered cases of TC with seminomatous element, 127 cases of pure TS were analyzed. All 127 patients with a median age of 37 years were pathologically diagnosed with orchiectomy specimens. Orchiectomy, chemotherapy, and radiotherapy were the main treatments for these patients. Patients with clinical stages I, II, and III testicular cancer of accounted for 81.1% (n=103), 15.7% (n=20), and 3.2% (n=4) of all patients, respectively. After a median follow-up time of 50 months, five patients presented with relapse during follow-up, and one among them died. Of the patients with stage I TS (T1N0M0S0 CS IA), three patients who only underwent orchiectomy relapsed. Among patients with stage II TS (T1N1M0S1 CS IIA), one patient relapsed after orchiectomy, post-surgery chemotherapy and radiotherapy. In four patients with stage III disease (T2N1M1aS1 CS IIIA), one relapsed after orchiectomy and chemotherapy, and died shortly after salvage chemotherapy and radiotherapy due to recurrence. The median overall survival time was 50 months. In all patients, the 2-year overall survival and progression-free survival probabilitis were 98.6% and 98.8%, respectively.

Conclusion: The present study shows that patients with TS have good prognosis even at an advanced stage. Surveillance after orchiectomy was important for patients with CSI seminoma, and we recommend cisplatin-based chemotherapy as salvage therapy for patients with CSI seminoma. In addition, patients with a maximal tumor diameter >4 cm should undergo post-surgery chemotherapy.
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http://dx.doi.org/10.2147/CMAR.S215537DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6698585PMC
August 2019

Novel Intumescent Flame Retardant Masterbatch Prepared through Different Processes and Its Application in EPDM/PP Thermoplastic Elastomer: Thermal Stability, Flame Retardancy, and Mechanical Properties.

Polymers (Basel) 2018 Dec 31;11(1). Epub 2018 Dec 31.

Key Laboratory of Advanced Materials Technology Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China.

In this work, the ethylene-propylene-diene monomer/polypropylene (EPDM/PP) thermoplastic elastomer filled with intumescent flame retardants (IFR) is fabricated by melting blend. The IFR are constituted with melamine phosphate-pentaerythritol (MP/PER) by compounding and reactive extruding, respectively. The effects of two kinds of MP/PER with different contents on the thermal stability, flame retardancy, and mechanical properties of materials are investigated by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), limiting oxygen index (LOI), UL-94, cone calorimeter test (CCT), and scanning electron microscopy (SEM). FTIR results show that the reactive extruded MP/PER partly generates melamine pyrophosphate (MPP) compared with compound masterbatches. TGA data indicate that the best thermal stability is achieved when the molar ratio of MP/PER reaches 1.8. All the reactive samples show a higher flame retardancy than compound ones. The CCT results also exhibit the same trend as above in heat release and smoke production rate. The EPDM/PP composites filled with 30 and 35% reactive MP/PER exhibit the improved flame retardancy but become stiffer and more brittle. SEM photos display that better dispersion and smaller particle size are obtained for reactive samples.
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http://dx.doi.org/10.3390/polym11010050DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6401871PMC
December 2018

The effect of thermo-oxidative ageing on crystallization, dynamic and static mechanical properties of long glass fibre-reinforced polyamide 10T composites.

R Soc Open Sci 2018 Jun 20;5(6):172029. Epub 2018 Jun 20.

Department of Polymer Material and Engineering, College of Materials and Metallurgy, Guizhou University, Guiyang 550025, People's Republic of China.

The performances and microstructure of long glass fibre-reinforced polyamide 10T (PA10T/LGF) composites that experienced different ageing temperatures (160 and 200°C) with increasing ageing time are characterized by differential scanning calorimetry (DSC), mechanical analysis, thermogravimetric analysis (TGA) and scanning electron microscopy to probe the correlation between properties of the composites and thermo-oxidative ageing. The DSC results show that PA10T/LGF composites occur on degradation, the fracture of molecular chains and the destruction of crystallization structure, which leads to the crystallization and melting peaks of PA10T/LGF composites to shift to high temperature. On the basis of dynamic mechanical analysis data, the reduction of the interfacial bonding between the glass fibre and PA10T matrix and the motion of molecular chain segments result in the thermo-oxidative ageing of composites. According to the calculation of activation energy (), thermo-oxidative temperature and ageing time can bring about the decline of the value, proving the deterioration in performance of PA10T/LGF composites. In view of TGA, the increase in the thermo-oxidative temperature and ageing time promotes the degradation of PA10T/LGF composites. The tensile, flexural and notched impact strengths of PA10T/LGF composites decline with prolonging the ageing temperature and time. The surface of materials produces some microcracks and the cross-section surface of PA10T/LGF composites becomes rougher.
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http://dx.doi.org/10.1098/rsos.172029DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6030261PMC
June 2018

[Forward efficacy of lacrimal passage obstruction treated by double frequency YAG laser].

Yan Ke Xue Bao 2005 Jun;21(2):82-3

Guangdong Huizhou People's Hospital, Huizhou 516002, China.

Purpose: To study the forward efficacy of lacrimal passage obstruction in different location treated by frequency-doubled YAG laser.

Methods: The forward efficacy of obstruction at different lacrimal passage located in 66 eyes from 64 cases treated by frequency-doubled Nd:YAG laser respectively were analyzed.

Results: The forward cure rate of stenosis of the puncta, dacryogogatresia, and common lacrimal duct stenosis is 100%, 94% and 89% respectively. As for dacryocystorhinostenosis, lower to 29%.

Conclusion: Frequency-doubled YAG laser is more fit for puncta stenosis, dacryogogatresia and common lacrimal duct stenosis. Choosing the other treatment is suitable to dacryocystorhinostenosis which is accompanied by chronic dacyocystitis for YAG laser' s poor forward efficacy.
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June 2005