bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Risk Factors for Septic Complications after Laparotomy for Abdominal Trauma: A Longitudinal Cohort Study
Authors: Gupta Rajan Prasad , Gupta Arun Kumar , Gupta Nikhil , Yelamanchi Raghav , Bansal Lalit Kumar , Durga CK
Published: May 2021

Introduction: Septic complications are the most common cause of death in trauma patients who survive beyond 48 hours. Early diagnosis and treatment of infectious complications is essential to prevent life-threatening complications like Systemic Inflammatory Response Syndrome (SIRS) and Multi-Organ Dysfunction Syndrome (MODS). Aim: To study the various risk factors for septic abdominal complications following laparotomy for trauma. Materials and Methods: A prospective longitudinal cohort single-center study was conducted from November 2016 to March 2018. Sixty patients above the age of 12 years, who underwent laparotomy for abdominal trauma in the Surgical Department of our hospital, were included in the study. Various patient variables were compared with postoperative septic abdominal complications like wound infection, wound dehiscence, anastomotic leak and intra-abdominal abscess. Data was analysed using Statistical Package for Social Sciences (SPSS) version 21.0. Results: In the total 60 patients (35.60±16.54), significant association was seen between wound infection and dehiscence with the time interval between trauma and surgery (p<0.001), lesser Revised Trauma Score (RTS) (p<0.001) and greater Injur Severity Score (ISS) (p<0.001). A significant association of all septic complications was seen with the need for Intensive Care Unit (ICU) stay (p<0.001) and the presence of associated injuries (p<0.001). Variables such as age, gender, co morbidities, Body Mass Index (BMI), pre-hospital care received, intraoperative findings and duration of ICU stay had no association with outcomes (p>0.05). Conclusion: In trauma patients, factors like low RTS score, high ISS score, need for ICU stay and the presence of associated injuries may help the surgeons to decide in which patients to go for techniques like delayed closure of the wound, stoma instead of bowel anastomosis, etc., which may help to reduce postoperative septic complications.
Tuberculosis Masking Hodgkin’s Lymphoma: A Case Report
Authors: Rustogi Nitin , Swain Bishakha
Published: May 2021

Concomitant Tuberculosis (TB) and Hodgkin’s Lymphoma (HL) is a rare entity, more commonly reported in the paediatric and adolescent populations. HL presents with fever, weight loss and lymphadenopathy. Disseminated TB also presents with fever, weight and appetite loss and generalised or localised lymphadenopathy with/without pulmonary symptoms. Both diseases together pose a diagnostic challenge for the clinicians because of the similar mode of presentation. This case report discusses the clinical scenario of a 48-year-old lady presenting with generalised lymphadenopathy and was initially diagnosed with disseminated TB. Due to clinical worsening despite regular Anti-TB Therapy (ATT), she was re-evaluated and later turned out to have co-existing HL.
Mortality Profile of Critical Patients in Medical Intensive Care Unit of Government Medical College of Central India
Authors: Tiwari Jyoti , Rawat Sumit , Jha Anju , Pandey Ramesh
Published: May 2021

Introduction: Mortality rate is always very high in Intensive Care Units (ICU) even with the best possible set ups, we should try to cater the need of the society according to the disease burden so that better care can be provided. Aim: To estimate the prevalence of various medical disease mortality profile of critically ill patients admitted in Medical Intensive Care Unit (MICU) of our institution. Materials and Methods: This was a retrospective observational study done at MICU of Bundelkhand Medical College and Hospital Sagar, Madhya Pradesh, India for a duration of one year (1st January 2019 to 31st December 2019). Data was retrieved from Medical Records Department (MRD) and total data of 349 deaths were registered. Disease was classified based upon ICD 10 (International Statistical classification of Diseases and related health problems) Score. Results: A total of 349 deaths occurred in MICU during the period of one year at the institution, out of which male deaths were 55.9% and Female deaths were 44.1%. MICU deaths occurred in higher numbers in males with Male: Female ratio of 1.2:1. This difference in ratio of male and female mortality was not statistically significant (p-value >0.05). Mean age of males at time of death was 58.4±16.3 years whereas mean age of females were 55.2±19.7 years. This difference in mortality with age and gender was not statistically significant (p-value >0.05). In present study, most common systemic causes of mortality were cardiovascular (29.8%), followed by respiratory (17.5%), renal (16.5%) and cerebrovascular diseases (13.8%). Mortality was documented in 276 (79%) individuals within duration of seven days of admission, whereas mortality in 46 (13.1%) and 27 (7.7%) cases were documented within 8 to 14 days and >14 days, respectively. The present study documented no statistically significant association between length of stay and age of patients (p-value >0.05). Conclusion: Cardiovascular diseases are the most common causes leading to mortality especially in elderly male patients. Also, higher number of deaths is reported within seven days of admission signifying severity of illness at the time of admission.
Kinetics of Diauxic Biogas Production from Energy Crops: Sunflower (Helianthus annus) and Napier Grass (Pennisetum purpureum) with Animal Manure
Authors: Opurum Christian C. , Nweke Christian O. , Nwanyanwu Christopher E. , Nwogu Nkemakolam A.
Published: May 2021

This study evaluated the kinetics of diauxic-like pattern of biogas production from energy crops, Sunflower (SF) and Napier grass (NG) with cow dung (CD). The tests were performed in a batch reactor (R) operation for 60 days in R1 - R4 and 53 days in R5 - R8 under mesophilic conditions (24 - 36OC). The characteristics of the tested energy crops suggest that they hold prospects for bioenergy production. The cumulative biogas yield/gVS showed that the best performance was R1 with a biogas yield of 15.17 dm3 (0.046 dm3/gVS) followed by R3, 13.90 dm3 (0.041 dm3/gVS) and R2, 11.01dm3 (0.032 dm3/gVS). A significant difference (P ≤ 0.05) in biogas yield was found in the reactors charged with SF/CD as against SF only. In the reactors that exhibited biphasic biogas production profile, two (2) kinetic parameters, K1 and K2 were determined by the bi-logistic function model. It was observed that the predicted values in the second phase (K2) of biogas production were considerably higher than the first phase (K1) in R2 - R5 as opposed to R6 - R8, which implies more biogas yield in phase 2 than phase 1. The results indicate that anaerobic digestion of SF and NG had a strong positive influence on biogas yield, BP, PR and λ1 but not for λ2. The bi-logistic function model suitably fitted the experimental data with a high correlation coefficient (R2) in the range of 0.986 - 0.997. Based on the kinetic parameters, the bi-logistic function model is well suited for the simulation of diauxic-like biogas production process.
Evaluation of Contamination Risks Due to the Sale and Storage Conditions of Smoked, Dried and Fresh Fishes in Ouagadougou
Authors: Ouedraogo Arouna , Zongo Cheikna , Tapsoba François , Cissé Hama , Traoré Yves , Savadogo Aly
Published: May 2021

Aims: Fish is a product more and more consumed in Burkina Faso, especially in Ouagadougou. Poor sale and storage conditions can impact on the hygienic quality of fish. The objective of this study was to identify the contamination risks due to the sale and storage conditions of smoked, dried and fresh fishes.

Study Design: A descriptive design was used to identify the different types and origins of fish on the markets in Ouagadougou and the practices and conditions of sale that could be sources of chemical and microbiological contamination.

Place and Duration of Study: Relevant data was collated in Ouagadougou (Burkina Faso) from February 2019 to July 2019.

Methodology: A survey was conducted among traders of dried and smoked fish from 50 markets and major sales sites in Ouagadougou. Data collection was done using a questionnaire developed with Sphinx Plus2 software.

Results: The results indicated a higher proportion of men (75%) than women (25%) with an age between 21 and 45 years old were participated in fish trade. The fish encountered in the markets of Ouagadougou come from Sourou, Kompienga and Bagré, as well as from external suppliers such as Côte d'Ivoire, Mali and Senegal. The different types of fish sold were dried or smoked carp (36.67%), smoked catfish (23.33%), dried Nanani or Djêdjê wala (concorde) (13.33%), smoked Macharon (10%), smoked Racok (10%) and smoked eels or Roolgo in mooré (local language) (6.67%). The types of fish most purchased by consumers, in order, were: Carp, Catfish, Macharon, Nanani. In addition, the study detected risks of contamination of the fish, namely: exposure material consisting of tables and baskets, conservation at room temperature, storage period of 10 to 30 days, no training in hygiene, fish served with bare hands, exposed to dust and stray animals.

Conclusion: In sum, the study revealed some characteristics of the fish industry in Ouagadougou and also risks of contamination of fish sold on the markets.
Evaluation of Storage Control Points and Implicated Pathogens on Fast Moving Consumer Goods in Suburbs of South-western Nigeria
Authors: Afolabi O. O. , Okonofua C.C. , Adigun M. O. , Dosumu E. , Aderoju R. B.
Published: May 2021

Food borne illness prevention system will depend on the extent of food safety control in place through food production, processing, distribution, keeping food at safe temperature and using safe water and raw materials. These stages of production are some of the important points determining food safety. This suggests the need to implement strict hygienic control measures along the food production chain during manufacturing, handling, storage and commercialization of foods. Ninety samples comprising of fifteen Milo (beverage), fifteen golden Morn (cereal), fifteen Maggi (seasoning), fifteen Lucozade boost (energy drink), fifteen Gala (Sausage) and fifteen Indomie (noodles) were collected from five stores of various shops in Lagos, Agbara and Sango Ogun State, Nigeria. Samples were processed and cultured using pour plate and streak plate techniques. Samples were cultured in five media consisting of four selective media and a basal media; Maconkey agar, Mannitol Salt agar, Salmonella Shigella agar, Eosin Methylene Blue agar and Nutrient agar. Differentiation and isolation of various isolates were based on gram-staining technique and biochemical reactions using OXOID MICROBAT TM identification kits. The in vitro assay revealed the presence of five bacteria species namely Staphylococcus aureus, Klebsiellia oxytoca, Proteus mirabilis, Yersinia pseudotuberculosis and Morganella morganii. Prevalence of the various isolates in the culture were found to be 67.66%, 11.27%, 9.77%, 7.51% and 3.75% respectively. The highest colony count (140.6) was obtained from samples (Maggi) from Agbara while the lowest colony count (21.0) was obtained from (Milo) Sango. The mean bacteria load of the isolates was 1.0*107CFU/ml. It was concluded that the hygienic quality of the sampled fast moving consumer products in term of microbiological standards compare favourably with international benchmarks as defined by Codex Alimentarius Commission all the observed ranges of aerobic colony count fall well below the upper threshold of microbial levels for class A products.
Assessment of Fertilizer Applicator while Spraying Fertilizers in Warangal and Nagarkurnool District, India
Authors: Jahan Afifa , Arunjyothi R.
Published: May 2021

Indian population is 73% depended on agricultural activities for their livelihood. Increasing population has increased the intensity of agricultural production for feeding and doubling of food production has increased usage of fertilizers. Spraying of fertilizers has reported to be a drudgery process by farmers. In the present study the fertilizer applicator developed by a farmer in wyra, Khammam district was studied in comparison to traditional practices of fertilization broadcasting and pocketing. The applicator studied in the present study is farmer friendly technology. Low cost Rs 2500 equipment which can be used with one labor and cattle pair. The results of the study concluded that with usage of fertilizer applicator the drudgery is reduced to 3 on REBA Scale which is low risk. It is cost effective and time saving technology compared to traditional fertilization methods of broadcasting fertilizers and pocketing fertilizers.
Strategic Environmental Assessment: Current Status, Practices and Challenges in Bangladesh
Authors: Hossan Md. Sahadat , Bari Md. Shafiqul , Rahman Md. Shoaibur , Hanif Md. Abu , Ali Md. Manik
Published: May 2021

Strategic environmental assessment (SEA) is an appraisal device of policies, plans, and programs and has evolved from an alternative of environmental impact assessment (EIA) to a potential environmental policy integration tool in national policy planning. Bangladesh has likewise rendered SEA in its environmental evaluation framework to consider environmental and social outcomes of policies, plans, and programs(PPPs), but the practice and current situation of SEA in Bangladesh is unknown to all. Considering this crisis the study was carried out to analyze the present status of SEA as well as to find out the constraints for successful SEA implementation in Bangladesh as an approach to integrate environmental considerations in the PPPs. The data were collected through multiple methodological techniques including document review as well as survey by standard questionnaire and key informant interviews (KIIs) with different stakeholders of the various backgrounds of Bangladesh related to policymaking. The study showed that SEA first appeared in Bangladesh in 2006 with the support of the World Bank as a donor agency and the first SEA was done in Bangladesh on the Dhaka metropolitan development plan in 2007. But through the enactment of the National Environmental Policy 2018, SEA gained formal status in the country. Now, This study also revealed that most of the organizations (government and non-government) i.e. 55.77 percent never practice SEA whereas only 15.38 percent of organizations of Bangladesh practice SEA on regular basis, and 28.85 percent of organizations practiced partially for assessing SEA in their proposed PPPs. A diverse list of constraints such as lack of political will, lacking awareness of SEA, inadequate finance, weak enforcement of environmental law, and inadequate knowledge of the implementation of SEA in PPPs were identified. Therefore, awareness building, capacity development, and proper training on SEA in Bangladesh are urgently needed.
Prevalence of Typhoid Fever in Franceville (Gabon): Case of the Sino-Gabonese Friendship Hospital; Retrospective Analysis of Clinical Data Over Three Years
Authors: Mba Thiery Ndong , Obiang Cédric Sima , Elvis Otogo N'Nang , Mombo Landry Eric , Ompana Mireille Andeme , Zogo Ulrich Kevin Ivala , Nkogué Judicaël Obame , Engonga Louis-Clément Obame , Ondo Joseph Privat , Bisseye Cyrille , Mickala Patrick
Published: May 2021

Typhoid fever is an infectious disease that is fatal if left untreated. The most recent global data show more than 20 million cases annually, with more than 200,000 deaths. In Gabon, a study has shown that young adults are increasingly affected. Nevertheless, national data on this scourge are rare. The aim is to determine the prevalence of typhoid fever at the Sino-Gabonese Friendship Hospital in Franceville. The data are confirmed cases of typhoid fever at the Sino-Gabonese Friendship Hospital in Franceville, entered into a database of the health information management system of the South-East Franceville Gabon Regional Health Directorate between January 2018 and December 2020. A trend analysis was conducted over time to establish correlations between the prevalence of typhoid fever and factors such as age, gender and time of year. To statistically analyze these data, measure incidence rates, and establish relationships between these values and their significance, we used R version 3.6.1 software. 2175 people suffered from typhoid fever during the three years of the study. Of these, 960 (44.07%) were men and 1215 (55.93%) were women. A 95% confidence interval was estimated and a value p≤0.05 was considered statistically significant. The age group 15-49 years was the most affected. Although cases occurred throughout the year, there were increasing cases of typhoid from 2018 to 2020 and a high prevalence during quarters 1 and 4. The prevalence over the years was 454 cases or 20.87% in 2018, 750 cases or 34.48% in 2019, and 971 cases or 44.65% in 2020. In Gabon, particularly in Franceville, typhoid fever is a real public health problem. To protect themselves against this disease and avoid possible epidemics, the health authorities and decision-makers must educate the population about the disease.
Response of Cabbage (Brassica oleracea var capitata L.) to Organic and Inorganic Fertilizer
Authors: Debrah P. Yaw , Afriyie-Debrah C. , Nuhu F. , Ribeiro P. Francisco , Obeng E. Agyei
Published: May 2021

Aim: The experiment was conducted in the Kintampo North Municipality during the 2017 cropping season from August to November to evaluate the response of cabbage to different soil amendments.

Methods: It was a single factor experiment laid out in a Randomized Complete Block design with three replications. The five treatments which includes NPK 15-15-15, poultry manure, cow dung and goat manure and a control.

Results: Parameters measured were plant height, number of leaves, leave length, canopy diameter, head diameter and head weight. Generally, all treatments performed better than the control used in the study.

Conclusions: Poultry manure performed similar to NPK 15-15-15, and were superior to all other treatments in all parameters measured. Cow dung and goat manure performed fairly well in the parameters measured.

Recommendation: The study therefore recommends the application of poultry manure for improved growth, yield maximization and sustainable cabbage production.  Application of cow dung and goat manure can also be adopted for appreciable yields of cabbage.
Synthesis, Drug Likeness and In-vitro Screening of Some Novel Quinazolinone Derivatives for Anti-Obesity Activity
Authors: Modh Pratik G. , Patel Laxman J.
Published: May 2021

Aim: A series of novel quinazolinone derivates was synthesized and assessed for their ability to inhibitory action on pancreatic lipase. The cyclization of quinazolinone-4(3H)-one derivatives was achieved, whereas carbon-carbon cross coupling reactions were carried out on cyclized quinazolinone-4(3H)-one. This synthesis method afforded corresponding 2, 3 and 6 substituted quinazolin-4(3H)-ones (3a to 3m) with moderate to high yields.

Methods: Benzamide derivatives (1a-1b) were synthesized from anthranilic acid using acid-amine reaction, followed by cyclization using catalytic p-toluene sulfonic acid and oxidation using (diacetoxyiodo)benzene to give bromo substituted quinazolin-4(3H)-ones (2a-2b), which were cross coupled to suitable boronic acid using Suzuki-Miyaura condition to obtain desired compound (3a-3m). All synthesized compounds were characterized by FTIR, proton NMR, LC-MS analysis, checked for their drug likeness, absorption and evaluated for in vitro pancreatic lipase inhibition activity.

Results: Analytical interpretation of all compounds with infrared, proton NMR and LC-MS spectroscopy confirmed their correct structure. All compounds (3a-3m) show good absorption and have reasonably good molecular properties except 3c and 3m which violate two criteria for Lipinski’s rule. Whereas, Compounds 3l and 3m showed IC50 value of 13.13±0.84 µg/mL and 13.80±1.27 µg/mL respectively comparable to the Orlistat (12.72±0.97µg/mL), a US FDA approved drug for the treatment of obesity.

Conclusion: Pancreatic lipase is an important lipolytic enzyme, synthesized and secreted through pancreas, plays an important role in dietary trigycerol absorption and metabolism. Therefore, reducing fat absorption through pancreatic lipase inhibition is a promising strategy to treat obesity. Based upon our findings, compounds 3l and 3m can be further developed as potent anti-obesity agents.
Understanding Pore Surface Modification of Sucrose-Modified Iron Oxide/Silica Mesoporous Composite for Degradation of Methylene Blue
Authors: Pertiwi Yuvita Eka , Ulfa Maria , Saraswati Teguh Endah , Prasetyoko Didik , Trisunaryanti Wega
Published: May 2021

Santa Barbara Amorphous (SBA-15) containing iron oxide with a sucrose-modified in a heterogeneous reaction for degradation methylene blue (MB) successful synthesized used hydrothermal, ultrasonication, and wet impregnation method. SBA-15 is mesoporous silica that can easily serve as external and internal surfaces making it suitable for a wide range of applications. The structure and morphology of materials were characterized using Surface Area Analyzer (SAA), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope-Energy Dispersive X-Ray (SEM-EDX), and Transmission Electron Microscopy (TEM). Iron oxide impregnated as a maghemite phase has an average size of 12 nm and well distributed on the SBA-15. After modified with sucrose the materials remaining stable, which has a two-dimensional hexagonal (p6mm) structure, high specific surface area, and large pore volume (up to 1.82 cm3.g−1). The degradation of MB was evaluated under visible light irradiation using UV-Vis spectroscopy. Catalytic activity showed efficiencies of 52.9; 70.2; and 21.1% for SBA-15, Fe2O3/SBA-15, and sucrose-modified Fe2O3/SBA-15 respectively. Sucrose-modified Fe2O3/SBA-15 has the lowest efficiency, which probably occurs due to the presence of pore-blocking and the formation of micropores on the external pore. The modification with sucrose has the advantage of producing a high surface area even though there is a catalytic center due to partial decomposition which causes a decrease in the efficiency of degradation of MB. All materials provide a high micro surface area so that they can be further adapted and can be widely applied to many potential applications as both catalyst support and an adsorbent. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
NIDA sets 5 mg of THC as standard cannabis unit for research
Authors: Knopf Alison
Published: May 2021

According to the National Institute on Drug Abuse (NIDA), one of the barriers to research on cannabis is the lack of a standard unit. “Existing experimental data are often hard to interpret due to the wide variability in potency of cannabis plant material and extracts, the lack of standard measures of use, and the wide variety of ways people consume cannabis,” according to a May 10 blog post by NIDA Director Nora Volkow, M.D. To help rectify this, NIDA, along with the National Cancer Institute; the National Heart, Lung, and Blood Institute; and the National Institute of Mental Health, published a notice in the NIH Guide (https://grants.nih.gov/grants/guide/notice‐files/NOT‐DA‐21‐049.html) directing researchers funded by these institutes to measure and report their findings from clinical research on cannabis using a standard unit of delta‐9‐tetrahydrocannabinol (THC) of 5 milligrams.
Reconstruction of Ultra‐thin Alveolar‐capillary Basement Membrane Mimics
Authors: Jain Puja , Nishiguchi Akihiro , Linz Georg , Wessling Matthias , Ludwig Andreas , Rossaint Rolf , Möller Martin , Singh Smriti
Published: May 2021

Alveolar‐capillary basement membrane (BM) is ultra‐thin (<2 µm) extracellular matrix that maintains integral epithelial‐endothelial cell layers. In vitro reconstructions of alveolar‐capillary barrier supported on synthetic scaffolds closely resembling the fibrous and ultra‐thin natural BM are essential in mimicking the lung pathophysiology. Although BM topology and dimensions are well known to significantly influence cellular behavior, conventionally used BM mimics fail to recreate this natural niche. To overcome this, electrospun ultra‐thin 2 µm poly(caprolactone) (PCL) nanofibrous mesh is used to establish an alveolar‐capillary barrier model of lung endothelial/epithelial cells. Transepithelial electrical resistance (TEER) and permeability studies reveal integral tight junctions and improved mass transport through the highly porous PCL meshes compared to conventional dense membranes with etched pores. The chemotaxis of neutrophils is shown across the barrier in presence of inflammatory response that is naturally impeded in confined regions. Conventional requirement of 3 µm or larger pore size can lead to barrier disruption due to epithelial/endothelial cell invasion. Despite high porosity, the interconnected BM mimic prevents barrier disruption and allows neutrophil transmigration, thereby demonstrating the physiological relevance of the thin nanofibrous meshes. It is envisioned that these bipolar cultured barriers would contribute to an organ‐level in vitro model for pathological disease, environmental pollutants, and nanotoxicology.
In Situ Observation of the Degradation Behavior and the Systematic Investigation of Corrosion Mechanism in AZ31 Alloy
Authors: Yan Xudong , Chen Lanyue , Xu Xiaofeng , Zhao Yuguang , Zhao Mingchun
Published: May 2021

The degradation behaviors of as‐received and as‐solutionized AZ31 alloys in Hanks’ solution are in situ studied by a 3D digital optical microscope. The initiation and extension processes of corrosion are investigated. Long‐time immersion and electrochemical tests are applied to investigate the corrosion mechanism systematically. The corrosion attacks of as‐received and as‐solutionized AZ31 alloy both start from the grain boundaries (with and without the Al8Mn5 phase) while show no preferential propagation, and the scratches also can act as the corrosion starting positions. The Al8Mn5 phase does not show an obvious accelerated effect on the Mg matrix's corrosion, and it also suffers corrosion. Solid solution treatment can enhance the corrosion resistance of AZ31 alloy is primarily due to the reduced dislocation density. Degradation products on as‐received AZ31 alloy are studied, the Al, Zn, and Mn elements degrade as Al2O3, ZnO, and MnO, respectively.
Integrating Bayesian Inference with Scanning Probe Experiments for Robust Identification of Surface Adsorbate Configurations
Authors: Järvi Jari , Alldritt Benjamin , Krejčí Ondřej , Todorović Milica , Liljeroth Peter , Rinke Patrick
Published: May 2021

Controlling the properties of organic/inorganic materials requires detailed knowledge of their molecular adsorption geometries. This is often unattainable, even with current state‐of‐the‐art tools. Visualizing the structure of complex non‐planar adsorbates with atomic force microscopy (AFM) is challenging, and identifying it computationally is intractable with conventional structure search. In this fresh approach, cross‐disciplinary tools are integrated for a robust and automated identification of 3D adsorbate configurations. Bayesian optimization is employed with first‐principles simulations for accurate and unbiased structure inference of multiple adsorbates. The corresponding AFM simulations then allow fingerprinting adsorbate structures that appear in AFM experimental images. In the instance of bulky (1S)‐camphor adsorbed on the Cu(111) surface, three matching AFM image contrasts are found, which allow correlating experimental image features to distinct cases of molecular adsorption.
Designing Hydrogels for 3D Cell Culture Using Dynamic Covalent Crosslinking
Authors: Rizwan Muhammad , Baker Alexander E. G. , Shoichet Molly S.
Published: May 2021

Designing simple biomaterials to replicate the biochemical and mechanical properties of tissues is an ongoing challenge in tissue engineering. For several decades, new biomaterials have been engineered using cytocompatible chemical reactions and spontaneous ligations via click chemistries to generate scaffolds and water swollen polymer networks, known as hydrogels, with tunable properties. However, most of these materials are static in nature, providing only macroscopic tunability of the scaffold mechanics, and do not reflect the dynamic environment of natural extracellular microenvironment. For more complex applications such as organoids or co‐culture systems, there remain opportunities to investigate cells that locally remodel and change the physicochemical properties within the matrices. In this review, advanced biomaterials where dynamic covalent chemistry is used to produce stable 3D cell culture models and high‐resolution constructs for both in vitro and in vivo applications, are discussed. The implications of dynamic covalent chemistry on viscoelastic properties of in vitro models are summarized, case studies in 3D cell culture are critically analyzed, and opportunities to further improve the performance of biomaterials for 3D tissue engineering are discussed.
Covalently Crosslinked Hydrogels via Step‐Growth Reactions: Crosslinking Chemistries, Polymers, and Clinical Impact
Authors: Gao Yongsheng , Peng Kevin , Mitragotri Samir
Published: May 2021

Hydrogels are an important class of biomaterials with the unique property of high‐water content in a crosslinked polymer network. In particular, chemically crosslinked hydrogels have made a great clinical impact in past years because of their desirable mechanical properties and tunability of structural and chemical properties. Various polymers and step‐growth crosslinking chemistries are harnessed for fabricating such covalently crosslinked hydrogels for translational research. However, selecting appropriate crosslinking chemistries and polymers for the intended clinical application is time‐consuming and challenging. It requires the integration of polymer chemistry knowledge with thoughtful crosslinking reaction design. This task becomes even more challenging when other factors such as the biological mechanisms of the pathology, practical administration routes, and regulatory requirements add additional constraints. In this review, key features of crosslinking chemistries and polymers commonly used for preparing translatable hydrogels are outlined and their performance in biological systems is summarized. The examples of effective polymer/crosslinking chemistry combinations that have yielded clinically approved hydrogel products are specifically highlighted. These hydrogel design parameters in the context of the regulatory process and clinical translation barriers, providing a guideline for the rational selection of polymer/crosslinking chemistry combinations to construct hydrogels with high translational potential are further considered.
Surface Wettability of Nanoparticle Modulated Sonothrombolysis
Authors: Wu Qingyuan , Zhang Fengrong , Pan Xueting , Huang Zhijun , Zeng Zhijie , Wang Hongyu , Jiao Jun , Xiong Xiaolu , Bai Lixin , Zhou Dongsheng , Liu Huiyu
Published: May 2021

Sonodynamic therapy (SDT) is a non‐invasive and highly penetrating treatment strategy under ultrasound irradiation. However, uncertainty in the mechanism of SDT has seriously hindered its future clinical application. Here, the mechanism of SDT enhanced by the wettability of nanoparticles is investigated. Nanoparticles can adsorb and stabilize nanobubbles in liquid, thus enhancing SDT efficiency. The stability of the nanobubbles is positively correlated with the desorption energy of the nanoparticles, which is determined by the wettability of the nanoparticles. This conclusion is verified for mesoporous silica and polystyrene nanoparticles and it is found that nanoparticles with a water contact angle of about 90° possess the largest desorption energy. To further apply this conclusion, thrombus models are constructed on rats and the experimental results demonstrate that nanoparticles with the largest desorption energy have the highest thrombolytic efficiency. It is believed that these findings will help to better understand the SDT mechanism and guide new strategies for rational design of nanoparticles adopted in SDT.
Divergent Paths, Same Goal: A Pair‐Electrosynthesis Tactic for Cost‐Efficient and Exclusive Formate Production by Metal–Organic‐Framework‐Derived 2D Electrocatalysts
Authors: Cao Changsheng , Ma Dong‐Dong , Jia Jingchun , Xu Qiang , Wu Xin‐Tao , Zhu Qi‐Long
Published: May 2021

Electrosynthesis of formic acid/formate is a promising alternative protocol to industrial processes. Herein, a pioneering pair‐electrosynthesis tactic is reported for exclusively producing formate via coupling selectively electrocatalytic methanol oxidation reaction (MOR) and CO2 reduction reaction (CO2RR), in which the electrode derived from Ni‐based metal–organic framework (Ni‐MOF) nanosheet arrays (Ni‐NF‐Af), as well as the Bi‐MOF‐derived ultrathin bismuthenes (Bi‐enes), both obtained through an in situ electrochemical conversion process, are used as efficient anodic and cathodic electrocatalysts, respectively, achieving concurrent yielding of the same high‐value product at both electrodes with greatly reduced energy input. The as‐prepared Ni‐NF‐Af only needs quite low potentials to reach large current densities (e.g., 100 mA cm−2@1.345 V) with ≈100% selectivity for anodic methanol‐to‐formate conversion. Meanwhile, for CO2RR in the cathode, the as‐prepared Bi‐enes can simultaneously exhibit near‐unity selectivity, large current densities, and good stability in a wide potential window toward formate production. Consequently, the coupled MOR//CO2RR system based on the distinctive MOF‐derived catalysts displays excellent performance for pair‐electrosynthesis of formate, delivering high current densities and nearly 100% selectivity for formate production in both the anode and the cathode. This work provides a novel way to design advanced MOF‐derived electrocatalysts and innovative electrolytic systems for electrochemical production of value‐added feedstocks.
Enhanced Electrochemical Kinetics with Highly Dispersed Conductive and Electrocatalytic Mediators for Lithium–Sulfur Batteries
Authors: Qian Ji , Xing Yi , Yang Yong , Li Yu , Yu Kaixin , Li Wanlong , Zhao Teng , Ye Yusheng , Li Li , Wu Feng , Chen Renjie
Published: May 2021

Lithium–sulfur (Li–S) batteries are promising energy‐storage devices because of their high theoretical energy densities. However, the practical application of Li–S batteries is still impeded by the poor cycling performance and rate capability at practical conditions. In order to improve the performance of practical Li–S batteries, a hierarchical Mo2C nanocluster/carbon nanosheets hybrid based hollow spherical material (Mo2C/CHS) is designed and prepared. The hollow spheres composed of stacked carbon nanosheets can facilitate the infiltration of electrolyte. The ultrasmall and highly conductive Mo2C nanocrystals are confined in the carbon nanosheets and expose more active sites for anchoring and conversion of lithium polysulfides and increase the number of the nuclei for Li2S2/Li2S precipitation. Benefitting from the synergistic effects, Mo2C/CHS greatly promotes electrochemical kinetics in Li–S batteries with high sulfur loading (5 mg cm−2). Even under lean electrolyte conditions (E/S = 7 μL mgsulfur−1), the Li–S batteries with Mo2C/CHS added exhibit a discharge capacity of 904 mAh g−1 at the high current rate of 0.5 C, and with 894 mAh g−1 maintained after 200 cycles. This work provides a fundamental understanding of the electrochemical processes and guides the rational design of host and additive materials for practical Li–S batteries.
Broadband Detection of X‐ray, Ultraviolet, and Near‐Infrared Photons using Solution‐Processed Perovskite–Lanthanide Nanotransducers
Authors: Xie Lili , Hong Zhongzhu , Zan Jie , Wu Qinxia , Yang Zhijian , Chen Xiaofeng , Ou Xiangyu , Song Xiaorong , He Yu , Li Juan , Chen Qiushui , Yang Huanghao
Published: May 2021

Solution‐processed metal‐halide perovskites hold great promise in developing next‐generation low‐cost, high‐performance photodetectors. However, the weak absorption of perovskites beyond the near‐infrared spectral region posts a stringent limitation on their use for broadband photodetectors. Here, the rational design and synthesis of an upconversion nanoparticles (UCNPs)–perovskite nanotransducer are presented, namely UCNPs@mSiO2@MAPbX3 (X = Cl, Br, or I), for broadband photon detection spanning from X‐rays, UV, to NIR. It is demonstrated that, by in situ crystallization and deliberately tuning the material composition in the lanthanide core and perovskites, the nanotransducers allow for a high stability and show a wide linear response to X‐rays of various dose rates, as well as UV/NIR photons of various power densities. The findings provide an opportunity to explore the next‐generation broadband photodetectors in the field of high‐quality imaging and optoelectronic devices.
Wood‐Derived Systems for Sustainable Oil/Water Separation
Authors: Fang Ying , Jing Chuyan , Li Guoliang , Ling Shengjie , Wang Zhaohui , Lu Ping , Li Qing , Dai Chenchen , Gao Sen , Chen Bailing , Bai Lulu , Zhang Hanqiu , Liu Tian , Wang Qingwen , Li Jian , Yu Haipeng , Liu Shouxin , Chen Wenshuai
Published: May 2021

Separating oil and water remains a serious challenge because various oil/water mixtures are generated in large quantities by industrial processes, unexpected accidents, and daily life. Various systems containing materials with specific structures and wettabilities have been investigated as possible solutions to this issue. As a sustainable biological material, wood and its derivatives have many advantageous properties for practical applications. The present review mainly focuses on recent progress in using wood‐derived systems for sustainable oil/water separation. Various types of materials that can be produced from wood are briefly introduced. Strategies for constructing wood‐derived separation materials based on direct use and integration, modification, and carbonization are then highlighted. Next, the use of wood‐derived systems for separating oil/water layered mixtures and oil/water emulsions by filtration and absorption methods are systematically discussed. The review concludes with a brief summary of some of the remaining challenges to be overcome.
A Prototypical Conjugated Polymer Regulating Signaling in Plants
Authors: Tullii Gabriele , Gobbo Federico , Costa Alex , Antognazza Maria Rosa
Published: May 2021

The use of nanomaterials has been very recently introduced in plant biotechnologies, for both the monitoring and the enhancement of plants functions. Several functional interfaces between living plants and nanotechnology have been successfully reported for diverse applications, from sensing to photosynthesis and energy production and from modulation of physiological activity to controlled delivery of chemicals. In this work, a photoactive, biohybrid interface based on a prototypical semiconducting polymer, sensitive to green light, and Arabidopsis thaliana plants is reported. Optical excitation of polymer beads is shown to deterministically regulate the Arabidopsis stomatal aperture, the leaf pores which regulate the plant carbon dioxide uptake, oxygen release, and transpiration processes. Moreover, it is observed that excitation of bio‐polymer hybrid interfaces optically modulates the cytosolic calcium ions concentration, which is involved, as a second messenger, in the regulation of stomatal movements. The results support the possibility to employ light‐responsive organic materials to regulate on demand the physiological activity of plant systems, in a drug‐free, touchless, and easily controllable way. When transferred to the field, this strategy may represent an innovative approach to optimize the exchange of gases and water loss of plants, and to improve the plant resilience toward environmental constraints.
Natural Hierarchically Structured Highly Porous Tomato Peel Based Tribo‐ and Piezo‐Electric Nanogenerator for Efficient Energy Harvesting
Authors: Saqib Qazi Muhammad , Khan Muhammad Umair , Song Hyunjae , Chougale Mahesh Y. , Shaukat Rayyan Ali , Kim Jungmin , Bae Jinho , Choi Min Joo , Kim Seong Chan , Kwon Ohbin , Bermak Amine
Published: May 2021

To mitigate future global energy challenges, it is vital to utilize natural resources to harness sustainable and environmentally‐friendly energy. This paper explores the tribo‐ and piezo‐electric functionalities of tomato peel (TP) to fabricate a nature‐driven hybrid nanogenerator. Tomato is one of the most cultivated vegetables globally, however, a significant amount of TP is disposed after utilization in the food processing industries. The TP possesses a natural hierarchically placed highly porous structure, which is helpful to enhance the output performance of both piezo‐ and tribo‐electric devices. This work shows that a TP based piezo‐electric nanogenerator can produce an open circuit voltage of 24.5 V, short circuit current of 2.5 µA, and maximum instantaneous power of 19.5 µW. In addition, the TP based tribo‐electric nanogenerator generates open circuit voltage, short circuit current, and instantaneous power of 135 V, 81 µA, and 3750 µW, respectively. Combining two NGs functionalities, the proposed TP based tribo‐ and piezo‐electric nanogenerator (TP‐TPENG) shows enhanced output performance with the rectified open circuit voltage, short circuit current, and maximum instantaneous power of 150 V, 84 µA, and 5400 µW, respectively. These results show that the TP‐TPENG can offer a new pathway toward bio‐based nanogeneration and self‐powered sensing green technologies.
Engineering Origami: A Comprehensive Review of Recent Applications, Design Methods, and Tools
Authors: Meloni Marco , Cai Jianguo , Zhang Qian , Sang‐Hoon Lee Daniel , Li Meng , Ma Ruijun , Parashkevov Teo Emilov , Feng Jian
Published: May 2021

Origami‐based designs refer to the application of the ancient art of origami to solve engineering problems of different nature. Despite being implemented at dimensions that range from the nano to the meter scale, origami‐based designs are always defined by the laws that govern their geometrical properties at any scale. It is thus not surprising to notice that the study of their applications has become of cross‐disciplinary interest. This article aims to review recent origami‐based applications in engineering, design methods and tools, with a focus on research outcomes from 2015 to 2020. First, an introduction to origami history, mathematical background and terminology is given. Origami‐based applications in engineering are reviewed largely in the following fields: biomedical engineering, architecture, robotics, space structures, biomimetic engineering, fold‐cores, and metamaterials. Second, design methods, design tools, and related manufacturing constraints are discussed. Finally, the article concludes with open questions and future challenges.
Atomically Dispersed Platinum Modulated by Sulfide as an Efficient Electrocatalyst for Hydrogen Evolution Reaction
Authors: Zhou Kai Ling , Han Chang Bao , Wang Zelin , Ke Xiaoxing , Wang Changhao , Jin Yuhong , Zhang Qianqian , Liu Jingbing , Wang Hao , Yan Hui
Published: May 2021

Catalytically active metals atomically dispersed on supports presents the ultimate atom utilization efficiency and cost‐effective pathway for electrocatalyst design. Optimizing the coordination nature of metal atoms represents the advanced strategy for enhancing the catalytic activity and the selectivity of single‐atom catalysts (SACs). Here, we designed a transition‐metal based sulfide‐Ni3S2 with abundant exposed Ni vacancies created by the interaction between chloride ions and the functional groups on the surface of Ni3S2 for the anchoring of atomically dispersed Pt (PtSA‐Ni3S2). The theoretical calculation reveals that unique Pt‐Ni3S2 support interaction increases the d orbital electron occupation at the Fermi level and leads to a shift‐down of the d ‐band center, which energetically enhances H2O adsorption and provides the optimum H binding sites. Introducing Pt into Ni position in Ni3S2 system can efficiently enhance electronic field distribution and construct a metallic‐state feature on the Pt sites by the orbital hybridization between S‐3p and Pt‐5d for improved reaction kinetics. Finally, the fabricated PtSA‐Ni3S2 SAC is supported by Ag nanowires network to construct a seamless conductive three‐dimensional (3D) nanostructure (PtSA‐Ni3S2@Ag NWs), and the developed catalyst shows an extremely great mass activity of 7.6 A mg−1 with 27‐time higher than the commercial Pt/C HER catalyst.
Large Tunnel Electroresistance with Ultrathin Hf0.5Zr0.5O2 Ferroelectric Tunnel Barriers
Authors: Prasad Bhagwati , Thakare Vishal , Kalitsov Alan , Zhang Zimeng , Terris Bruce , Ramesh Ramamoorthy
Published: May 2021

Hafnia‐based ferroelectric tunnel junctions (FTJs) hold great promise for nonvolatile memory and emerging data storage applications. In this article, a large tunnel electroresistance effect with ultrathin Hf0.5Zr0.5O2 (HZO) barrier based FTJs is reported. Robust ferroelectricity is achieved with ≈1 nm films by stabilizing the rhombohedral polar phase of HZO (R‐HZO) through a large compressive strain, induced by growing the film epitaxially on a SrTiO3 (001) substrate. The OFF/ON ratio of the junction resistance at zero bias is about 135 with ≈1 nm thick barrier, which increases to ≈105 with increasing the barrier thickness to ≈2.5 nm. The resistance‐area product (RA) of tunnel junctions is reduced by nearly three orders of magnitude by using an ≈1 nm R‐HZO barrier as compared with typically reported RA values for doped‐HfO2 barrier based FTJs, which significantly improves signal‐to‐noise ratio during the read operation. These results set the stage for further exploration of Hafnia‐based FTJs for non‐volatile memory applications.
Simultaneously Improved Thermoelectric and Mechanical Properties Driven by MgB2 Doping in Bi0.4Sb1.6Te3 Based Alloys
Authors: Qin Haixu , Cui Bo , Wang Wei , Sun Sibo , Qin Dandan , Guo Muchun , Xie Liangjun , Guo Fengkai , Cai Wei , Sui Jiehe
Published: May 2021

Bi2Te3‐based alloys are the most mature and widely used thermoelectric materials since their zT value has been significantly improved in past decades. However, the poor mechanical strength and machinability derived from the easy cleavage along basal planes not only produce many scraps in the device fabrication process but also lead the devices unstable in the actual service. In this work, a tiny amount of MgB2 is induced in the Bi0.4Sb1.6Te3 alloy to simultaneously enhance the thermoelectric and mechanical properties. In detail, magnesium atoms occupy the bismuth/antimony sites to optimize the carrier concentration and suppress the bipolar effect, pushing the average zT value up to 1.16 ranging from 300 to 500 K, which catches up with the current highest level in p‐type Bi2Te3‐based materials. Moreover, the precipitation phase, boron nanoparticles, distributed at the grain boundaries can effectively improve the compressive strength from 166 to 239 MPa. The prominent thermoelectric and mechanical properties endow the materials with great potential for commercial applications.