Publications by authors named "Muhammad Humayun"

29 Publications

  • Page 1 of 1

Near-Field Energy Transfer into Silicon Inversely Proportional to Distance Using Quasi-2D Colloidal Quantum Well Donors.

Small 2021 Sep 12:e2103524. Epub 2021 Sep 12.

Department of Electrical and Electronics Engineering, Department of Physics, UNAM - Institute of Materials Science and Nanotechnology, Bilkent University, Ankara, 06800, Turkey.

Silicon is the most prevalent material system for light-harvesting applications; however, its inherent indirect bandgap and consequent weak absorption limits its potential in optoelectronics. This paper proposes to address this limitation by combining the sensitization of silicon with extraordinarily large absorption cross sections of quasi-2D colloidal quantum well nanoplatelets (NPLs) and to demonstrate excitation transfer from these NPLs to bulk silicon. Here, the distance dependency, d, of the resulting Förster resonant energy transfer from the NPL monolayer into a silicon substrate is systematically studied by tuning the thickness of a spacer layer (of Al O ) in between them (varied from 1 to 50 nm in thickness). A slowly varying distance dependence of d with 25% efficiency at a donor-acceptor distance of 20 nm is observed. These results are corroborated with full electromagnetic solutions, which show that the inverse distance relationship emanates from the delocalized electric field intensity across both the NPL layer and the silicon because of the excitation of strong in-plane dipoles in the NPL monolayer. These findings pave the way for using colloidal NPLs as strong light-harvesting donors in combination with crystalline silicon as an acceptor medium for application in photovoltaic devices and other optoelectronic platforms.
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http://dx.doi.org/10.1002/smll.202103524DOI Listing
September 2021

Electrochemical Reduction of CO: A Review of Cobalt Based Catalysts for Carbon Dioxide Conversion to Fuels.

Nanomaterials (Basel) 2021 Aug 9;11(8). Epub 2021 Aug 9.

Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall TR10 9FE, UK.

Electrochemical CO reduction reaction (CORR) provides a promising approach to curbing harmful emissions contributing to global warming. However, several challenges hinder the commercialization of this technology, including high overpotentials, electrode instability, and low Faradic efficiencies of desirable products. Several materials have been developed to overcome these challenges. This mini-review discusses the recent performance of various cobalt (Co) electrocatalysts, including Co-single atom, Co-multi metals, Co-complexes, Co-based metal-organic frameworks (MOFs), Co-based covalent organic frameworks (COFs), Co-nitrides, and Co-oxides. These materials are reviewed with respect to their stability of facilitating CO conversion to valuable products, and a summary of the current literature is highlighted, along with future perspectives for the development of efficient CORR.
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http://dx.doi.org/10.3390/nano11082029DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8400998PMC
August 2021

Corrigendum to "Fabrication of BiFeO-g-CN-WO Z-scheme heterojunction as highly efficient visible-light photocatalyst for water reduction and 2,4-dichlorophenol degradation: Insight mechanism" [J. Hazard. Mater. 397 (2020) 122708].

J Hazard Mater 2021 Aug 7;421:126772. Epub 2021 Aug 7.

Engineering Research Center for Functional Ceramics of the Ministry of Education, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, PR China; China-EU Institute for Clean and Renewable Energy, Huazhong University of Science and Technology, Wuhan 430074, PR China.

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http://dx.doi.org/10.1016/j.jhazmat.2021.126772DOI Listing
August 2021

Experiences of Outpatient Clinics and Opinions of Telehealth by Caucasian and South Asian Patients' With Celiac Disease.

J Patient Exp 2021 19;8:23743735211018083. Epub 2021 May 19.

University of Roehampton, London, United Kingdom.

Outpatient clinics are an important part of chronic disease management, including that of celiac disease. During the coronavirus disease 2019 (COVID-19) global pandemic, telephone and online video consultations with health care professionals have substantially increased. This study aimed to explore the experience and opinions of adults, with celiac disease, toward face-to-face clinic appointments and alternatives, such as telehealth. Semistructured qualitative interviews with 37 patients were undertaken (75% White Caucasians, 25% South Asians; 29 patients were not adhering to the gluten-free diet). Interviews were recorded, transcribed, and analyzed by NVivo. Frequently reported issues with face-to-face appointments included travel and car parking costs, needing to take time off work, and frequent changes to appointment time. In addition, South Asian patients highlighted issues with linguistics barriers. Telephone consultations were considered acceptable and practical by the majority of patients based on ease and convenience. Online video consultations were favored by just 9 patients, however it is acknowledged that since the COVID-19 pandemic, there has been a greater exposure to this type of technology. These patient experiences can inform health care service development and are not biased by external health concerns connected with in-person visits during the pandemic.
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http://dx.doi.org/10.1177/23743735211018083DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8205329PMC
May 2021

Child physical abuse: awareness and practices of medical and dental doctors in Pakistan.

J Pak Med Assoc 2021 Jun;71(6):1704-1708

Department of Community Health Sciences, Hamdard College of Medicine & Dentistry, Hamdard University, Karachi, Pakistan.

Objective: To determine the awareness and practices of doctors and dentists in detecting and reporting suspected cases of child physical abuse.

Methods: The cross-sectional study was conducted from November 2017 to June 2018 at the Hamdard College of Medicine and Dentistry, Karachi, and comprised doctors and dentists practising in public and private hospitals across Pakistan. Data was collected using a predesigned questionnaire to assess knowledge of the social indicators of child physical abuse, response to child physical abuse, and actions taken by the professionals when they believed a child abuse case had been detected. Data was analysed using SPSS 22.

Results: Of the 575 healthcare professionals, 371(64.5%) were doctors and 204(35.5%) were dentists; 347(60.3%) were males; 446(77.6%) were working in private hospitals; 384(66.8%) had <10 years of experience; and 99(17.2%) had received formal training of child abuse. While 450(78.3%) subjects strongly agreed on the value of identifying and documenting child physical abuse, 336(58%) did not take any action in suspected cases.

Conclusions: Although doctors and dentists had a positive attitude regarding child physical abuse, the majority preferred to remain silent in suspected cases.
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http://dx.doi.org/10.47391/JPMA.1233DOI Listing
June 2021

Self-Resonant Microlasers of Colloidal Quantum Wells Constructed by Direct Deep Patterning.

Nano Lett 2021 Jun 24;21(11):4598-4605. Epub 2021 May 24.

Department of Electrical and Electronics Engineering Department of Physics, UNAM-Institute of Materials Science and Nanotechnology, Bilkent University, Ankara 06800, Turkey.

Here, the first account of self-resonant fully colloidal μ-lasers made from colloidal quantum well (CQW) solution is reported. A deep patterning technique is developed to fabricate well-defined high aspect-ratio on-chip CQW resonators made of grating waveguides and in-plane reflectors. The fabricated waveguide-coupled laser, enabling tight optical confinement, assures in-plane lasing. CQWs of the patterned layers are closed-packed with sharp edges and residual-free lifted-off surfaces. Additionally, the method is successfully applied to various nanoparticles including colloidal quantum dots and metal nanoparticles. It is observed that the patterning process does not affect the nanocrystals (NCs) immobilized in the attained patterns and the different physical and chemical properties of the NCs remain pristine. Thanks to the deep patterning capability of the proposed method, patterns of NCs with subwavelength lateral feature sizes and micron-scale heights can possibly be fabricated in high aspect ratios.
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http://dx.doi.org/10.1021/acs.nanolett.1c00464DOI Listing
June 2021

A rational design of g-CN-based ternary composite for highly efficient H generation and 2,4-DCP degradation.

J Colloid Interface Sci 2021 Oct 20;599:484-496. Epub 2021 Apr 20.

Engineering Research Center for Functional Ceramics of the Ministry of Education, School of Optical and Electronic Information, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, PR China; Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, PR China. Electronic address:

In this work, g-CN based ternary composite (CeO/CN/NH-MIL-101(Fe)) has been fabricated via hydrothermal and wet-chemical methods. The composite showed superior photoactivities for HO reduction to produce H and 2,4-dichlorophenol (2,4-DCP) degradation. The amount of H evolved over the composite under visible and UV-visible irradiations is 147.4 µmol·g·h and 556.2 µmol·g·h, respectively. Further, the photocatalyst degraded 87% of 2,4-DCP in 2 hrs under visible light irradiations. The improved photoactivities are accredited to the synergistic-effects caused by the proper band alignment with close interfacial contact of the three components that significantly promoted charge transfer and separation. The 2,4-DCP degradation over the composite is dominated by OH radical rather than h and O as investigated by scavenger trapping experiments. This is further supported by the electron para-magnetic resonance (EPR) study. This work provides new directions for the development of g-CN based highly efficient ternary composite materials for clean energy generation and pollution control.
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http://dx.doi.org/10.1016/j.jcis.2021.04.049DOI Listing
October 2021

An Overview of the Recent Progress in Polymeric Carbon Nitride Based Photocatalysis.

Chem Rec 2021 Jul 22;21(7):1811-1844. Epub 2021 Apr 22.

Engineering Research Center for Functional Ceramics of the Ministry of Education, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, PR, China.

Recently, polymeric carbon nitride (g-C N ) as a proficient photo-catalyst has been effectively employed in photocatalysis for energy conversion, storage, and pollutants degradation due to its low cost, robustness, and environmentally friendly nature. The critical review summarized the recent development, fundamentals, nanostructures design, advantages, and challenges of g-C N (CN), as potential future photoactive material. The review also discusses the latest information on the improvement of CN-based heterojunctions including Type-II, Z-scheme, metal/CN Schottky junctions, noble [email protected], [email protected], carbon nanotubes (CNTs)@CN, metal-organic frameworks (MOFs)/CN, layered double hydroxides (LDH)/CN heterojunctions and CN-based heterostructures for H production from H O, CO conversion and pollutants degradation in detail. The optical absorption, electronic behavior, charge separation and transfer, and bandgap alignment of CN-based heterojunctions are discussed elaborately. The correlations between CN-based heterostructures and photocatalytic activities are described excessively. Besides, the prospects of CN-based heterostructures for energy production, storage, and pollutants degradation are discussed.
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http://dx.doi.org/10.1002/tcr.202100067DOI Listing
July 2021

Neurological manifestation of coeliac disease with particular emphasis on gluten ataxia and immunological injury: a review article.

Gastroenterol Hepatol Bed Bench 2021 ;14(1):1-7

Dudley Group of Hospitals NHSF Trust, UK.

Coeliac disease (CD) is a gluten-induced enteropathy affecting 1% of the population and has extra intestinal manifestations. One such expression involves nervous system, and CD may present as gluten ataxia (GA), peripheral neuropathy and epileptiform disorder among others. Considerable controversy exists on the exact pathophysiological mechanism of gluten leading to ataxia. It is, however, clear that in intestinal axis tissue transglutaminase 2 (tTG2) is the primary target but in the nervous system, tTG6 may be the causative antigen although its exact role is not clear. Furthermore, it has also been postulated that anti-gangliodise antibodies may play a role in the emergence of central pathology if not the key contender. Moreover, the association of neurological injury with non-coeliac gluten sensitivity (NCGS), a related but pathologically different condition implies an independent mechanism of neuronal injury by gluten in the absence of CD. This review will touch on the salient features of CD and the nervous system and will highlight current controversies in relation to gluten and GA.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8035534PMC
January 2021

Water-assisted colonoscopy: an international modified Delphi review on definitions and practice recommendations.

Gastrointest Endosc 2021 06 16;93(6):1411-1420.e18. Epub 2020 Oct 16.

Division of Gastroenterology and Hepatology, Stanford University School of Medicine, VA Palo Alto, California, United States.

Background And Aims: Since 2008, a plethora of research studies has compared the efficacy of water-assisted (aided) colonoscopy (WAC) and underwater resection (UWR) of colorectal lesions with standard colonoscopy. We reviewed and graded the research evidence with potential clinical application. We conducted a modified Delphi consensus among experienced colonoscopists on definitions and practice of water immersion (WI), water exchange (WE), and UWR.

Methods: Major databases were searched to obtain research reports that could potentially shape clinical practice related to WAC and UWR. Pertinent references were graded (Grading of Recommendations, Assessment, Development and Evaluation). Extracted data supporting evidence-based statements were tabulated and provided to respondents. We received responses from 55 (85% surveyed) experienced colonoscopists (37 experts and 18 nonexperts in WAC) from 16 countries in 3 rounds. Voting was conducted anonymously in the second and third round, with ≥80% agreement defined as consensus. We aimed to obtain consensus in all statements.

Results: In the first and the second modified Delphi rounds, 20 proposed statements were decreased to 14 and then 11 statements. After the third round, the combined responses from all respondents depicted the consensus in 11 statements (S): definitions of WI (S1) and WE (S2), procedural features (S3-S5), impact on bowel cleanliness (S6), adenoma detection (S7), pain score (S8), and UWR (S9-S11).

Conclusions: The most important consensus statements are that WI and WE are not the same in implementation and outcomes. Because studies that could potentially shape clinical practice of WAC and UWR were chosen for review, this modified Delphi consensus supports recommendations for the use of WAC in clinical practice.
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http://dx.doi.org/10.1016/j.gie.2020.10.011DOI Listing
June 2021

Homozygous variants of EDAR underlying hypohidrotic ectodermal dysplasia in three consanguineous families.

Eur J Dermatol 2020 Aug;30(4):408-416

Department of Biochemistry, Hazara University, Mansehra, Khyber Pakhtunkhwa, Pakistan.

Background: Hypohidrotic ectodermal dysplasia (HED) is a congenital anomaly characterized by hypohydrosis, hypotrichosis and hypodontia. Mutations in at least four genes (EDAR, EDARADD, WNT10A, TRAF6) have been reported to cause both autosomal recessive and autosomal dominant forms of HED. Mutations in two other genes (EDA and IKBKG) have been reported to cause X-linked HED.

Objectives: To clinically characterize three consanguineous families (A-C) segregating with autosomal recessive HED and identify possible disease-causing variants of EDAR and EDARADD genes.

Materials And Methods: The genes, EDAR and EDARADD, were sequenced in Family A and C, and exome sequencing was performed in Family B. Additionally, in Family A and C, the effect of the identified variants was examined by analysis of EDAR mRNA, extracted from hair follicles from both affected and unaffected members.

Results: Sequence analysis revealed three possible disease-causing EDAR variants including a novel splice acceptor site variant (IVS3-1G > A) in Family A and two previously reported mutations (p.[Ala26Val], p.[Arg25*]) in the two other families. Previously, the nonsense variant p.(Arg25*) was reported only in the heterozygous state. Analysis of the RNA, extracted from hair follicles, revealed skipping of a downstream exon in EDAR and complete degradation of EDAR mRNA in affected members in family A and C, respectively. Computational modelling validated the pathogenic effect of the two variants identified in Family B and C.

Conclusion: The three variants reported here expand the spectrum of EDAR mutations associated with HED which may further facilitate genetic counselling of families segregating with similar disorders in the Pakistani population.
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http://dx.doi.org/10.1684/ejd.2020.3844DOI Listing
August 2020

Zenker's Diverticulum: Can Protocolised Measurements with Barium SWALLOW Predict Severity and Treatment Outcomes? The "Zen-Rad" Study.

Dysphagia 2021 Jun 19;36(3):393-401. Epub 2020 Jun 19.

Radiology Department, Russells Hall Hospital, Dudley, UK.

Although barium swallow imaging is established in the investigation of Zenker's diverticulum (ZD), no agreed measurement protocol exists. We developed a protocol for measuring ZD dimensions and aimed to correlate measurements with symptoms and post-operative outcomes. This prospective study included patients with confirmed ZD who underwent flexible endoscopic septal division (FESD) between 2014 and 2018. ZD was confirmed on barium radiology with measurements reviewed by two consultant radiologists. Symptom severity pre- and post-FESD was measured using the Dysphagia, Regurgitation, Complications (DRC) scale. Regression analyses were conducted to identify dimensions associated with therapeutic success, defined as remission (DRC score ≤ 1) 6 months after index FESD. In total, 67 patients (mean age 74.3) were included. Interobserver reliability (intraclass correlation coefficients-ICCs) was greatest for pouch width (0.981) and pouch depth (0.934), but not oesophageal depth (0.018). Male gender (60.9%) was associated with larger pouch height (P = 0.008) and width (P = 0.004). A positive correlation was identified between baseline DRC score and pouch depth (ρ 0.326, P = 0.011), particularly the regurgitation subset score (ρ 0.330, P = 0.020). The index pouch depth was associated with FESD procedure time (rho 0.358, P = 0.041). Therapeutic success was achieved in 64.2% and was associated with shorter pouch height (median 14.5 mm vs. 19.0 mm, P = 0.030), pouch width (median 19.9 mm vs. 28.8 mm, P = 0.34) and cricopharyngeal length (median 20.2 mm vs. 26.3 mm, P = 0.036). ZD dimensions may be feasible and were evaluated using Barium radiology. Specific parameters appear to correlate with severity and post-FESD outcomes, which aid with pre-procedural planning.
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http://dx.doi.org/10.1007/s00455-020-10148-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8163680PMC
June 2021

Fabrication of BiFeO-g-CN-WO Z-scheme heterojunction as highly efficient visible-light photocatalyst for water reduction and 2,4-dichlorophenol degradation: Insight mechanism.

J Hazard Mater 2020 Oct 20;397:122708. Epub 2020 Apr 20.

Engineering Research Center for Functional Ceramics of the Ministry of Education, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, PR China; China-EU Institute for Clean and Renewable Energy, HuazhongUniversity of Science and Technology, Wuhan 430074, PR China. Electronic address:

In this work, a Z-scheme BiFeO-g-CN-WO (BFO-CN-WO) photocatalyst has been synthesized via a wet chemical method and utilized in photocatalysis for hydrogen generation and 2,4-dichlorophenol (2,4-DCP) degradation under visible light irradiation. The resultant photocatalyst showed 90 μmol·h g H evolution activity and 63% 2,4-DCP degradation performance, which is 12 and 4.2 times higher than the pristine g-CN respectively. The fascinating photocatalytic performance is attributed to the strong interfacial contact between g-CN and the coupled BiFeO and WO component, which greatly improved the visible light absorption and charge carriers' separation. The designed Z-scheme heterojunction is a successful strategy for enhancing the separation efficiency of photo-induced charge carriers at the interface while retaining outstanding redox ability. During 2,4-DCP degradation, LC/MS technique was used to detect the reaction intermediates. According to the LC/MS results, several new intermediates such as 2,3-dichloro-6-(2,4-dichlorophenoxy)phenol (m/z = 306), 2,4-dichlorophenyl hydrogen carbonate (m/z = 207), 2,4-dichlorobenzen-1,3-diol (m/z = 177) and phenyl hydrogen carbonate (m/z = 137) were detected. Based on these intermediates, 2,4-DCP degradation pathway is proposed. The fluorescence (FL) and electron paramagnetic resonance (EPR) results reveal that the •OH plays an important role in the 2,4-DCP degradation. The fabricated photocatalyst can be utilized in the field of photocatalysis for practical applications.
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http://dx.doi.org/10.1016/j.jhazmat.2020.122708DOI Listing
October 2020

Experimental and DFT Studies of Au Deposition Over WO/g-CN Z-Scheme Heterojunction.

Nanomicro Lett 2019 Dec 19;12(1). Epub 2019 Dec 19.

Engineering Research Center for Functional Ceramics of the Ministry of Education, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, People's Republic of China.

A typical Z-scheme system is composed of two photocatalysts which generate two sets of charge carriers and split water into H and O at different locations. Scientists are struggling to enhance the efficiencies of these systems by maximizing their light absorption, engineering more stable redox couples, and discovering new O and H evolutions co-catalysts. In this work, Au decorated WO/g-CN Z-scheme nanocomposites are fabricated via wet-chemical and photo-deposition methods. The nanocomposites are utilized in photocatalysis for H production and 2,4-dichlorophenol (2,4-DCP) degradation. It is investigated that the optimized 4Au/6% WO/CN nanocomposite is highly efficient for production of 69.9 and 307.3 µmol h g H gas, respectively, under visible-light (λ > 420 nm) and UV-visible illumination. Further, the fabricated 4Au/6% WO/CN nanocomposite is significant (i.e., 100% degradation in 2 h) for 2,4-DCP degradation under visible light and highly stable in photocatalysis. A significant 4.17% quantum efficiency is recorded for H production at wavelength 420 nm. This enhanced performance is attributed to the improved charge separation and the surface plasmon resonance effect of Au nanoparticles. Solid-state density functional theory simulations are performed to countercheck and validate our experimental data. Positive surface formation energy, high charge transfer, and strong non-bonding interaction via electrostatic forces confirm the stability of 4Au/6% WO/CN interface.
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http://dx.doi.org/10.1007/s40820-019-0345-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7770730PMC
December 2019

Biallelic mutations in the LPAR6 gene causing autosomal recessive wooly hair/hypotrichosis phenotype in five Pakistani families.

Int J Dermatol 2019 Aug 11;58(8):946-952. Epub 2019 May 11.

Institute of Biochemistry, University of Balochistan, Quetta, Pakistan.

Background: Autosomal recessive wooly hair/hypotrichosis is an inherited disorder of hair characterized by less dense, short, and tightly curled hair on the scalp and sometimes less dense to complete absence of eyebrows and eyelashes. Autosomal recessive wooly hair/hypotrichosis phenotypes are mostly associated with pathogenic sequence variants in LIPH and LPAR6 genes.

Methods: To find out the molecular basis of the disease, five families with autosomal recessive wooly hair/hypotrichosis were recruited for genetic analysis. Direct Sanger sequencing of LIPH and LPAR6 genes was carried out using BigDye chain termination chemistry. P2RY5 protein homology models were developed to study the effect of mutation on protein structure in a family having novel mutation.

Results: Sanger sequencing revealed a novel homozygous missense mutation (c.47A>T) in the LPAR6 gene in family A, while recurrent mutation (c.436G>A) was detected in the rest of the four families (B-E). Protein homology models for both native and mutant P2RY5 protein were developed to study the difference in subtle structural features because of Lys16Met (K16M) mutation. We observed that P2RY5 mutation results decrease in the number of ionic interactions detrimental to the protein stability. Protein modeling studies revealed that the novel mutation identified here decreased the number of ionic interactions by affecting physicochemical parameters of the protein, leading to an overall decrease in protein stability with no major secondary structural changes.

Conclusion: The molecular analysis further confirms the frequent involvement of LPAR6 in autosomal recessive wooly hair/hypotrichosis, while the bioinformatic study revealed that the missense mutation destabilizes the overall structure of P2RY5 protein.
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http://dx.doi.org/10.1111/ijd.14480DOI Listing
August 2019

Photodegradation of 2,4-dichlorophenol and rhodamine B over n-type ZnO/p-type BiFeO heterojunctions: detailed reaction pathway and mechanism.

Environ Sci Pollut Res Int 2019 Jun 27;26(17):17696-17706. Epub 2019 Apr 27.

China-EU Institute for Clean and Renewable Energy, Huazhong University of Science and Technology, Wuhan, 430074, People's Republic of China.

The development of new technologies for efficient degradation of pollutant has been an increasing demand in the globe due to the serious environmental issues. Herein, we report n-type ZnO/p-type BiFeO composites as highly efficient visible light nanophotocatalysts prepared via a wet chemical solution method. Based on the measurements of OH-related fluorescence (FL) spectra, photoluminescence (PL) spectra, photoelectrochemical I-V curves, and electrochemical impedance spectra (EIS), it is demonstrated that the photo-induced charge carrier (electron-hole pairs) in the as-prepared n-type ZnO/p-type BiFeO composites with proper amount of the coupled ZnO (10% by mass) exhibits high separation compared with the bare BiFeO (BFO) nanoparticles. This is well responsible for the superior visible light photocatalytic performance of the composites for 2,4-dichlorophenol (2,4-DCP) and rhodamine B (RhB) degradation. It is confirmed by means of scavenger test and liquid chromatography-tandem mass spectrometry (LC/MS) analysis of the intermediate products that OH is the pre-dominant oxidant involved in the degradation of 2,4-DCP. A detailed reaction pathway for 2,4-dichlorophenol degradation over the amount-optimized ZnO/BFO composite is proposed mainly based on the LC/MS product ions. This work will provide a feasible route to design and develop BFO-based highly efficient visible light-active photocatalysts for environmental purification and could be extended to other visible light-active semiconductor materials.
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http://dx.doi.org/10.1007/s11356-019-05079-0DOI Listing
June 2019

Highly efficient degradation of 2,4-dichlorophenol over CeO/g-CN composites under visible-light irradiation: Detailed reaction pathway and mechanism.

J Hazard Mater 2019 02 31;364:635-644. Epub 2018 Oct 31.

Engineering Research Center for Functional Ceramics of the Ministry of Education, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, PR China. Electronic address:

Herein, we report for the first time the highly efficient degradation of 2,4-dichlorophenol (2,4-DCP) over CeO/g-CN composites (xCeO/CN) prepared via wet-chemical solution method. It is shown that the resultant nanocomposites with a proper mass ratio percentage (15%) of CeO coupled exhibit greatly enhanced visible-light activity for 2,4-dichlorophenol (2,4-DCP) degradation compared to the bare g-CN. From photoluminescence (PL) and Fluorescence (FL) results, it is suggested that enhanced photo-degradation is attributed to the significantly improved charge separation and transfer as a result of the proper band alignments between g-CN and CeO components. Further, from radical trapping experiments, it is confirmed that hydroxyl radicals (OH) are the predominant oxidants involved in the degradation of 2,4-DCP over CeO/CN composites. Furthermore, a possible reaction pathway and detailed photocatalytic mechanism for 2,4-DCP degradation is proposed mainly based on the detected liquid chromatography tandem mass spectrometry (LC-MS) intermediate products, that readily transform into CO and HO. This work would help researchers to deeply understand the reaction mechanism of 2,4-DCP and would provide feasible routes to fabricate g-CN-based highly efficient photocatalysts for environmental remediation.
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http://dx.doi.org/10.1016/j.jhazmat.2018.10.088DOI Listing
February 2019

Spatial intensity profiling of elastic and inelastic scattering in isotropic and anisotropic liquids by immersion of a spherical silicon photocell.

Appl Opt 2017 Dec;56(34):9384-9389

The transverse spatial intensity distribution of elastic and inelastic light scattering in passive and active as well as weak and strong scattering liquid media has been studied by using Sphelar One p-n junction silicon spherical photocells. We immersed a Sphelar One in these scattering solutions and measured the photoconductive response in reverse biased photodiode (PD) configuration. The passive weak scattering medium was pure ethanol (EtOH), whereas the passive strong scattering medium was 5CB nematic liquid crystal (NLC). Solutions of 0.1 mM Rhodamine 640 perchlorate laser dye in EtOH and in 5CB NLC were used as active scattering media. The response of Sphelar One was strongly enhanced in 5CB NLC compared to EtOH, as well as in active solutions compared to passive solutions. The morphology of the Sphelar One is already advantageous over conventional one-sided planar PDs inside liquid solutions. This omnidirectional response of the Sphelar One can further be enhanced by optimizing the properties of the surrounding passive elastic and active inelastic scatterers.
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http://dx.doi.org/10.1364/AO.56.009384DOI Listing
December 2017

Adherence to a Gluten Free Diet Is Associated with Receiving Gluten Free Foods on Prescription and Understanding Food Labelling.

Nutrients 2017 Jul 6;9(7). Epub 2017 Jul 6.

Health Sciences Research Centre, University of Roehampton, London SW15 4JD, UK.

Treatment of coeliac disease requires a strict gluten-free (GF) diet, however, a high proportion of patients do not adhere to a GF diet. The study explores the practical challenges of a GF diet and dietary adherence in Caucasian and South Asian adults with coeliac disease. Patients with biopsy- and serology-proven coeliac disease were recruited from a hospital database. Participants completed a postal survey ( = 375), including a validated questionnaire designed to measure GF dietary adherence. Half of Caucasians (53%) and South Asians (53%) were adhering to a GF diet. The quarter of patients ( = 97) not receiving GF foods on prescription had a lower GF dietary adherence score compared with those receiving GF foods on prescription (12.5 versus 16.0; < 0.001). Not understanding food labelling and non-membership of Coeliac UK were also associated with lower GF dietary adherence scores. A higher proportion of South Asian patients, compared with Caucasians, reported difficulties understanding what they can eat (76% versus 5%; < 0.001) and understanding of food labels (53% versus 4%; < 0.001). We recommend retaining GF foods on prescription, membership of a coeliac society, and regular consultations with a dietitian to enable better understanding of food labels. Robust studies are urgently needed to evaluate the impact of reducing the amount of GF foods prescribed on adherence to a GF diet in all population groups.
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http://dx.doi.org/10.3390/nu9070705DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5537820PMC
July 2017

Exceptional Visible-Light Activities of TiO-Coupled N-Doped Porous Perovskite LaFeO for 2,4-Dichlorophenol Decomposition and CO Conversion.

Environ Sci Technol 2016 12 7;50(24):13600-13610. Epub 2016 Dec 7.

Key Laboratory of Functional Inorganic Materials Chemistry, Heilongjiang University , Ministry of Education, School of Chemistry and Materials Science, International Joint Research Center for Catalytic Technology, Harbin 150080, P. R. China.

In this work, TiO-coupled N-doped porous perovskite-type LaFeO nanocomposites as highly efficient, cheap, stable, and visible-light photocatalysts have successfully been prepared via wet chemical processes. It is shown that the amount-optimized nanocomposite exhibits exceptional visible-light photocatalytic activities for 2,4-dichlorophenol (2,4-DCP) degradation by ∼3-time enhancement and for CO conversion to fuels by ∼4-time enhancement, compared to the resulting porous LaFeO with rather high photoactivity due to its large surface area. It is clearly demonstrated, by means of various experimental data, especially for the ·OH amount evaluation, that the obviously enhanced photoactivities are attributed to the increased specific surface area by introducing pores, to the extended visible-light absorption by doping N to create surface states, and to the promoted charge transfer and separation by coupling TiO. Moreover, it is confirmed from radical trapping experiments that the photogenerated holes are the predominant oxidants in the photocatalytic degradation of 2,4-DCP. Furthermore, a possible photocatalytic degradation mechanism for 2,4-DCP is proposed mainly based on the resultant crucial intermediate, 2-chlorosuccinic acid with m/z = 153, that readily transform into CO and HO. This work opens up a new feasible route to synthesize visible-light-responsive high-activity perovskite-type nanophotocatalysts for efficient environmental remediation and energy production.
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http://dx.doi.org/10.1021/acs.est.6b04958DOI Listing
December 2016

Diagnosis and Surveillance of Barrett's Esophagus: Addressing the Transatlantic Divide.

Dig Dis Sci 2016 08 1;61(8):2185-2193. Epub 2016 Apr 1.

Gastroenterology Department, Dudley Group Hospitals, Birmingham City University, Birmingham, UK.

Background: Barrett's esophagus is a premalignant condition of the esophagus leading to esophageal adenocarcinoma. No consensus exists between the UK and USA concerning the diagnosis of Barrett's esophagus. Although the diagnostic procedure is common, the required findings and diagnostic criteria vary. Both guidelines require endoscopy showing columnar epithelia lining the esophagus, but the US guidelines require the additional finding of intestinal metaplasia on biopsy to confirm diagnosis. Achievement of a consensus is of particular importance due to the established progression from Barrett's esophagus to esophageal adenocarcinoma. Of further importance is the increasing incidence of esophageal adenocarcinoma, a condition with poor overall survival, leading to various opinions on the utility of surveillance in patients.

Discussion: A review of the vast array of literature revealed that substantial evidence exists in favor of both diagnostic criteria; hence, there is no easy way to identify the "correct" method of diagnosing Barrett's esophagus. USA recommends surveillance of Barrett's esophagus, whereas UK does not advocate it unless dysplasia is present. Surveillance was found to be effective, but this varied as did cost-effectiveness. Further research into diagnostic methods for Barrett's esophagus is needed to address areas of limited understanding, such that agreement can be reached and practice standardized. Surveillance was generally advocated, but with different criteria and time intervals, and new methods are being evaluated.
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http://dx.doi.org/10.1007/s10620-016-4138-xDOI Listing
August 2016

Exceptional performance of photoelectrochemical water oxidation of single-crystal rutile TiO2 nanorods dependent on the hole trapping of modified chloride.

Sci Rep 2016 Feb 24;6:21430. Epub 2016 Feb 24.

Key Laboratory of Functional Inorganic Materials Chemistry (Heilongjiang University), Ministry of Education, National Center for International Research of Catalytic technology, School of Chemistry and Materials Science, Harbin 150080, P.R. China.

It is highly desired to effectively trap photogenerated holes for efficient photoelectrochemical (PEC) water oxidation to evolve O2 on oxide semiconductors. Herein, it is found for the first time mainly based on the time-resolved- and atmosphere-controlled- surface photovoltage responses that the modified chloride would effectively trap photogenerated holes so as to prolong the charge lifetime and hence promote charge separation of single-crystal rutile TiO2 nanorods. Its strong capacity to trap holes, comparable to the widely-used methanol and Co(II) phosphate, is well responsible for the exceptional photoactivities for PEC water oxidation to evolve O2 on rutile nanorods with a proper amount of chloride modified, about 2.5-time high as that on the resulting anatase nanoparticles, even 10-time if the surface area is considered. Moreover, it is suggested that the hole trapping role of chemically-adsorbed chloride is related to its lonely-pair electrons, and to the subsequently-produced intermediate Cl atoms with proper electronegativity for evolving O2. Interestingly, this finding is also applicable to the chloride-modified anatase TiO2. This work will provide a feasible strategy to design high-activity nanostructured semiconductor photoanodes for PEC water oxidation, even for overall water splitting.
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http://dx.doi.org/10.1038/srep21430DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4764924PMC
February 2016

Coupling of Nanocrystalline Anatase TiO₂ to Porous Nanosized LaFeO₃ for Efficient Visible-Light Photocatalytic Degradation of Pollutants.

Nanomaterials (Basel) 2016 Jan 20;6(1). Epub 2016 Jan 20.

Key Laboratory of Functional Inorganic Materials Chemistry, Ministry of Education, School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080, China.

In this work we have successfully fabricated nanocrystalline anatase TiO₂/perovskite-type porous nanosized LaFeO₃ (T/P-LFO) nanocomposites using a simple wet chemical method. It is clearly demonstrated by means of atmosphere-controlled steady-state surface photovoltage spectroscopy (SPS) responses, photoluminescence spectra, and fluorescence spectra related to the formed OH radical amount that the photogenerated charge carriers in the resultant T/P-LFO nanocomposites with a proper mole ratio percentage of TiO₂ display much higher separation in comparison to the P-LFO alone. This is highly responsible for the improved visible-light activities of T/P-LFO nanocomposites for photocatalytic degradation of gas-phase acetaldehyde and liquid-phase phenol. This work will provide a feasible route to synthesize visible-light responsive nano-photocatalysts for efficient solar energy utilization.
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http://dx.doi.org/10.3390/nano6010022DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5302529PMC
January 2016

The promotion effect of surface negative electrostatic field on the photogenerated charge separation of BiVO4 and its contribution to the enhanced PEC water oxidation.

Chem Commun (Camb) 2015 Feb;51(14):2821-3

Key Laboratory of Functional Inorganic Materials Chemistry (Heilongjiang University), Ministry of Education, School of Chemistry and Materials Science, Harbin 150080, P. R. China.

The increased surface-carried negative charge of BiVO4 after phosphate modification prolongs the photogenerated charge carrier lifetime and improves the separation by inducing the holes to transfer to the surface, leading to the obvious enhancement of visible light activities for PEC water oxidation.
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http://dx.doi.org/10.1039/c4cc08835bDOI Listing
February 2015

Assessment of potential toxicity of a smokeless tobacco product (naswar) available on the Pakistani market.

Tob Control 2012 Jul 3;21(4):396-401. Epub 2011 Jun 3.

Department of Pharmacy, University of Peshawar, Peshawar, Pakistan.

Background: 'Naswar' is a smokeless tobacco product (STP) widely used in Pakistan. It has been correlated with oral and oesophageal cancer in recent clinical studies. The toxic effects associated with STPs have been associated with trace level contaminants present in these products. The toxin levels of Pakistani naswar are reported for the first time in this study.

Methods: A total of 30 Pakistani brands of naswar were tested for a variety of toxic constituents and carcinogens such as cadmium, arsenic, lead and other carcinogenic metals, nitrite and nitrate, and nicotine and pH.

Results: The average values of all the toxins studied were well above their allowable limits, making the product a health risk for consumers. Calculated lifetime cancer risk from cadmium and lead was 1 lac (100,000) to 10 lac (1,000,000) times higher than the minimum 10E-4 (0.00001) to 10E-6 (0.000001), which is the 'target range' for potentially hazardous substances, according to the US Environmental Protection Agency. Similarly, the level of arsenic was in the range of 0.15 to 14.04 μg/g, the average being 1.25 μg/g. The estimated average bioavailable concentration of arsenic is 0.125-0.25 μg/g, which is higher than the allowable standard of 0.01 μg/g. Similarly, the average minimum daily intake of chromium and nickel was 126.97 μg and 122.01 μg, as compared to allowable 30-35 μg and 35 μg, respectively; a 4-5 times higher exposure. However, beryllium was not detected in any of the brands studied. The pH was highly basic, averaging 8.56, which favours the formation of tobacco specific amines thus making the product potentially toxic. This study validates clinical studies correlating incidence of cancer with naswar use in Pakistan.

Conclusions: This study shows that the production, packaging, sale and consumption of naswar should be regulated so as to protect the public from the health hazards associated with its consumption.
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http://dx.doi.org/10.1136/tc.2010.042630DOI Listing
July 2012

Exhumation--a key to provide justice to victims of homicide: situation in Larkana and Sukkur divisions.

J Ayub Med Coll Abbottabad 2010 Jan-Mar;22(1):168-70

Department of Forensic Medicine, Bannu Medical College, Bannu, Pakistan.

Background: Foul play in cases of hurt and homicide is an established fact. People on basis of enmity falsely charge their enemies; this practice is carried out globally. The purpose of present study was to know the situation in the study area and also to know the risk factors which make hindrance in providing justice in exhumed cases.

Methods: The present study was conducted over a period of 3 and half years from July 2006 to Dec 2009. During the said period total 21 exhumations were carried out in Sukkur and Larkana Divisions by the team of Chandka Medical College, Larkana. Cases were studied in Forensic Medicine Department of Chandka Medical College, Larkana. Out of 21 cases, only 9 cases were positive (autopsy). In rest of 12 cases, autopsy reports remained undetermined due to advanced decomposition/putrefaction of corpses.

Results: During the study period, total 21 exhumations (autopsies) were carried out in different districts of Larkana and Sukkur divisions. There were 17 male cases and 4 female cases. Cases were divided in to 4 groups on age basis. Group-1 from 0-5 years, Group-2 from 16-30 years, Group-3 from 31-45 years, Group-4 from 46-65 years. The maximum number of cases fall in group-2 which are 15 (71.42%) and minimum in group-1 which is 1 (4.76%). Out of 21 cases, only in 9 cases cause of death was ascertained and majority of these were firearm injuries (5, 55.55%), two (22.22%) cases of drowning, one (11.11%) strangulation and one blunt trauma. The success rate remained 42.85%. Nineteen cases were of primary autopsy (First time) on exhumation and 2 cases were secondary (re-examination).

Conclusion: The success rate in challenge cases depends mostly on the duration of exhumation and soil of cemetery. If a foul play is suspected then there should be no unnecessary delay in conduction of exhumation. If exhumation is carried out within days after burial, 90% results can be achieved.
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April 2011

Changing pattern of fabricated injuries in Larkana region.

J Ayub Med Coll Abbottabad 2009 Jul-Sep;21(3):76-8

Department of Forensic Medicine and Toxicology, Chandka Medical College, Larkana, Pakistan.

Background: Man has been egotist by nature and from Ancient time man has been endeavouring to bring under power other human beings. With the passage of time and growth of civilization this trend has been increased. Now there are more dangerous ways of violence and torture in use for twisting and turning people around. Inflection of fabricated injuries is one of the ways for fulfilment of his lust. Incidence of fabricated injuries is related with crime rate in any society, and this practice is carried out through out the world. Fabricated Injury is a major problem which forensic expert/causality medical officer face during their duty. Very little literature is available regarding study of fabricated injuries and no authentic criteria has so for been developed for labelling an injury as fabricated one.

Methodology: The present study is about 130 challenged medico-legal cases in Larkana Division which were studied in special medical board held in the Department of Urology Chandka Medical College Larkana. Out of 130 cases 50 were proved to be fabricated.

Results: The total number of challenged cases was 130, out of these 50 (38.46%) cases were of fabricated injuries. Out of 50 fabricated cases, 46 (92%) were males and 4 (8%) were female, thus the male to female ratio was approximately 11:1. Maximum cases (25) were from Larkana District, 15 cases were from Shikarpur and 10 cases from Jacobabad. The majority of fabricated injuries from Larkana District were nose injuries as out of 25 fabricated injuries from Larkana district 10 were nasal injuries, while from district Jacobabad and Shikarpur there was no nasal fabricated injury.

Conclusion: Most of the fabricated injuries are caused on accessible part of the body like arms, legs, abdomen, chest etc. The pattern of fabricated injuries is changing in Larkana District as out of 25 fabricated injuries in this district 10 were nasal injuries while in District Jacobabad and Shikarpur there was no nasal fabricated injury.
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November 2010

Analysis of homicidal deaths in district DI Khan: an autopsy study.

J Ayub Med Coll Abbottabad 2009 Jan-Mar;21(1):155-7

Department of Forensic Medicine & Toxicology, Gomal Medical College, DI Khan, Pakistan.

Background: One of the oldest crimes in human civilization is homicide which started from murder of Abel by the hands of Cane. With the passage of time manner of homicide have been changing. Study of pattern of homicide in any civil society is the first step towards development of intervention to reduce the impact of homicidal crimes. This study was conducted at the department of forensic medicine and toxicology Gomal Medical College DI Khan to know the pattern of the homicides, taking it as the first step in the prevention of crime.

Methods: The present study was conducted over two years 2007-08. The data collected includes all reported unnatural deaths from the urban and rural areas of district on which autopsies were conducted in the district headquarter teaching hospital DI Khan and department of Forensic Medicine and Toxicology, Gomal Medical College DL Khan.

Results: Homicidal deaths constituted 259/341 (76%) of all autopsies. Out of these homicides 59.07% were caused by the firearm. The most common firearm weapons were high velocity rifled weapons (AK-47, rifles and pistols). A total of 304 injuries were found in various body regions giving an average of about two injuries per victim/person. The head, neck and face sustained the highest numbers of injuries 100, (32.90%) followed by chest 91 (29.93%) and abdomen 47 (15.4%); the extremities, buttock and genitalia together sustained 65 (21.38 %) injuries. A part from firearm injuries unfortunately in our this study the second highest cause of homicidal deaths was bomb blasts injuries either due to suicide bombers or remote control bombs. The numbers of deaths due to blast injuries were 82 for the year 2007/08 out of total homicidal deaths and percentage was 32.66%.

Conclusion: The vast majority of homicidal deaths in this area are caused by firearms like other big cities of the province like Peshawar, which bring up issues related to possession of firearms and change in cultural attitude towards the use of firearm, if a decrease in firearm related homicides is desired.
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May 2011

Intraocular ophthalmic ointment following clear corneal phacoemulsification: Clinical implications.

J Cataract Refract Surg 2006 Dec;32(12):2135-8

Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada.

We report 4 cases of apparent ophthalmic ointment in the anterior chamber after sutureless clear corneal phacoemulsification and posterior chamber intraocular lens implantation. The cases, as well as previous literature, indicate that ointment for topical use can be well tolerated in the eye, although glaucoma and uveitis can be potential negative outcomes. Possible risk factors, some of which may be related to current rates of endophthalmitis after clear corneal cataract surgery, and methods to prevent intraocular ophthalmic ointment after cataract surgery are discussed.
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http://dx.doi.org/10.1016/j.jcrs.2006.08.034DOI Listing
December 2006
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