bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protection afforded by post-infection SARS-CoV-2 vaccine doses: A cohort study in Shanghai
Authors: Zheng Bo , Gonçalves Bronner P , Deng Pengfei , Wang Weibing , Tian Jie , Liang Xueyao , Yao Ye , Xue Caoyi 
Published: April 2024

Background:In many settings, a large fraction of the population has both been vaccinated against and infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Hence, quantifying the protection provided by post-infection vaccination has become critical for policy. We aimed to estimate the protective effect against SARS-CoV-2 reinfection of an additional vaccine dose after an initial Omicron variant infection.Methods:We report a retrospective, population-based cohort study performed in Shanghai, China, using electronic databases with information on SARS-CoV-2 infections and vaccination history. We compared reinfection incidence by post-infection vaccination status in individuals initially infected during the April–May 2022 Omicron variant surge in Shanghai and who had been vaccinated before that period. Cox models were fit to estimate adjusted hazard ratios (aHRs).Results:275,896 individuals were diagnosed with real-time polymerase chain reaction-confirmed SARS-CoV-2 infection in April–May 2022; 199,312/275,896 were included in analyses on the effect of a post-infection vaccine dose. Post-infection vaccination provided protection against reinfection (aHR 0.82; 95% confidence interval 0.79–0.85). For patients who had received one, two, or three vaccine doses before their first infection, hazard ratios for the post-infection vaccination effect were 0.84 (0.76–0.93), 0.87 (0.83–0.90), and 0.96 (0.74–1.23), respectively. Post-infection vaccination within 30 and 90 days before the second Omicron wave provided different degrees of protection (in aHR): 0.51 (0.44–0.58) and 0.67 (0.61–0.74), respectively. Moreover, for all vaccine types, but to different extents, a post-infection dose given to individuals who were fully vaccinated before first infection was protective.Conclusions:In previously vaccinated and infected individuals, an additional vaccine dose provided protection against Omicron variant reinfection. These observations will inform future policy decisions on COVID-19 vaccination in China and other countries.Funding:This study was funded the Key Discipline Program of Pudong New Area Health System (PWZxk2022-25), the Development and Application of Intelligent Epidemic Surveillance and AI Analysis System (21002411400), the Shanghai Public Health System Construction (GWVI-11.2-XD08), the Shanghai Health Commission Key Disciplines (GWVI-11.1-02), the Shanghai Health Commission Clinical Research Program (20214Y0020), the Shanghai Natural Science Foundation (22ZR1414600), and the Shanghai Young Health Talents Program (2022YQ076).
General and Academic Vocabulary Sizes and Reading Comprehension among the First Year BSED English Students
Authors: Cawagdan-Cuarto Harieth , Cuenca Pia , Gonito Judy-Ann , Lyka Maan Kalaw 
Published: April 2024

Proficiency in the English language comprises a wide range of skills, including listening, speaking, reading, and writing. Among these skills, reading comprehension holds particular importance as it enables students to effectively process and understand written text. An essential factor contributing to successful reading comprehension is vocabulary, which plays a fundamental role in the reading process. This study aimed to explore the relationship between reading comprehension and vocabulary, specifically focusing on general and academic vocabulary commonly used in English learning and academic settings. The research utilized a descriptive-correlational method, employing Pearson’s r method to establish a significant relationship between the two variables. The results revealed significant findings for each type of vocabulary and reading comprehension. The learners demonstrated a very high general vocabulary and an above-average academic vocabulary size. Additionally, the learners exhibited an average level of reading comprehension. These statistical findings emphasize the significant relationship between the variables studied, emphasizing their mutual influence. To enhance students’ academic performance, the researchers suggest implementing modules comprising diverse activities and exercises to promote the development of both academic vocabulary and reading comprehension skills.
Gaining insight into long‐term effects of inviting speculation: Does recantation help?
Authors: Compo Nadja Schreiber , Parker Janat F. 
Published: July 2009

AbstractThe effects of speculation on delayed recall and on source monitoring (SM) as a recantation device were examined in first and fourth graders. Two weeks after a clown show, the speculation group recalled all actions and speculated on half. The control group recalled all actions without speculating. One month and 6 months later, all children recalled all actions. Half the children were given the opportunity to recant at 1 month and all children at 6 months. Even after 6 months, speculation negatively impacted recall. Only first‐graders' script‐consistent false responses increased with time. In the speculation group, 19% of previously given script‐consistent speculations were recanted after 1 month and 20% after 6 months. Older children were better at recanting than younger children. Although recantation via SM immediately after 6‐month recall had a positive effect, SM at 1 month had no prospective effect on 6‐month recall. Copyright © 2009 John Wiley & Sons, Ltd.
Nanoscale Phase Separation and High Photovoltaic Efficiency in Solution‐Processed, Small‐Molecule Bulk Heterojunction Solar Cells
Authors: Walker Bright , Tamayo Arnold B. , Dang Xuan‐Dung , Zalar Peter , Seo Jung Hwa , Garcia Andres , Tantiwiwat Mananya , Nguyen Thuc‐Quyen 
Published: July 2009

AbstractResearch relating to organic solar cells based on solution‐processed, bulk heterojunction (BHJ) films has been dominated by polymeric donor materials, as they typically have better film‐forming characteristics and film morphology than their small‐molecule counterparts. Despite these morphological advantages, semiconducting polymers suffer from synthetic reproducibility and difficult purification procedures, which hinder their commercial viability. Here, a non‐polymeric, diketopyrrolopyrrole‐based donor material that can be solution processed with a fullerene acceptor to produce good quality films is reported. Thermal annealing leads to suitable phase separation and material distribution so that highly effective BHJ morphologies are obtained. The frontier orbitals of the material are well aligned with those of the fullerene acceptor, allowing efficient electron transfer and suitable open‐circuit voltages, leading to power conversion efficiencies of 4.4 ± 0.4% under AM1.5G illumination (100 mW cm−2). Small molecules can therefore be solution processed to form high‐quality BHJ films, which may be used for low‐cost, flexible organic solar cells.
Effect of styrene addition on polystyrene molecular degradation by Lewis acids
Authors: Díaz Mónica F. , Barbosa Silvia E. , Capiati Numa J. 
Published: July 2009

AbstractThe polystyrene molecule can suffer chain scission by beta‐cleavage mechanism in the presence of Lewis acids. This is an undesirable secondary reaction, particularly when the Friedel‐Crafts alkylation is applied to immiscible polyolefin/polystyrene (PS) blends compatibilization. It competes with the main copolymerization reaction, degrading the PS and impairing the properties of the blend. A simple experimental procedure of styrene (St) addition is proposed to compensate the PS degradation. The effect of St on the chain scission is studied by the PS molecular weight variation and reaction gases evolution. Some hypotheses are worked out to get a basic description of this complex cationic reactive process. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effect of damp‐heat aging on the properties of ethylene‐vinyl acetate copolymer and ethylene‐ acrylic acid copolymer blends
Authors: Chen Shuangjun , Zhang Jun , Su Jun 
Published: July 2009

AbstractThe aim of this investigation is to evaluate the effect of damp‐heat aging on properties of ethylene‐vinyl acetate (EVA) copolymer (14 wt % vinyl acetate units), ethylene‐acrylic acid (EAA) copolymer (8 wt % acrylic acid units) and their blends. Attenuated total reflection Fourier transform infrared spectrum (ATR‐FTIR), differential scanning calorimeter (DSC), wide angle X‐ray diffraction (WAXD), and mechanical tests are employed to investigate the changes of copolymer blends' structures and properties. ATR‐FTIR tests show that increase of carbonyl index is owing to the incorporation of oxygen into the polymeric chain of EVA in the blends and has not much influence on the EAA. By DSC measurements, the low temperature endothermic peak (Tm2) of various EAA/EVA blends at about 43.7°C attributed to the secondary crystallization is increased with the aging time, which means the lamellar thickness of low temperature crystallite is increased. The increase of low temperature peaks probably derives from the interphase or even amorphous parts of both EVA and EAA components. The crystalline size detected by WAXD and degree of crystalline have both been improved by damp‐heat aging. By mechanical tests, the sample has more hardness, more modulus at 100% extension ratio, more tensile strength with less elongation at break as the proportion of EAA increase. Aging influence will induce deterioration of mechanical properties, and increase of degree of crystallinity can make the hardness, the modulus at 100% extension ratio and tensile strength increase. The two factors will both have effect on the mechanical properties of EAA/EVA blends. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Preparation and characterization of poly(L‐lactide) membranes prepared by γ‐radiation‐induced grafting of N‐vinyl pyrrolidone
Authors: Chen Hao , Peng Chaorong , Yao Yongyi , Wang Jingxia , Chen Zhuping , Yang Zhirong , Xia Lijun , Liu Siyang 
Published: July 2009

AbstractA copolymer, poly(L‐lactide)‐g‐poly(N‐vinyl pyrrolidone) (PLLA‐g‐PVP) was prepared with poly(L‐lactide) (PLLA) and N‐vinyl pyrrolidone in the presence of methanol as a solvent by γ‐ray irradiation. The structure of PLLA‐g‐PVP was characterized by 1H‐NMR and Fourier transform infrared spectroscopy. The PLLA‐g‐PVP graft ratio calculated by the percentage increase in weight increased with the increase of absorbed dose, and the percentage crystallinity of PLLA‐g‐PVP decreased with increasing graft ratio. The introduction of the poly(N‐vinyl pyrrolidone) chain into PLLA resulted in a decrease in the contact angle of PLLA‐g‐PVP with increasing graft ratio. In vitro degradation testing showed that PLLA‐g‐PVP had a higher degradation rate both in the weight‐loss test and molecular weight measurement because of a lower crystalline percentage and higher hydrophilicity compared to PLLA. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Novel sulfonated polyimide ionomers by incorporating pyridine functional group in the polymer backbone
Authors: Lei Rui , Kang Chuanqing , Huang Yunjie , Li Yuhan , Wang Xi , Jin Rizhe , Qiu Xuepeng , Ji Xiangling , Xing Wei , Gao Lianxun 
Published: July 2009

AbstractA series of sulfonated polyimides (SPIs) containing pyridine ring in the polymer backbone were synthesized by the polycondensation of 1,4,5,8‐naphthalene‐tetracarboxylic dianhydride (NTDA), 5‐(2,6‐bis(4‐aminophenyl)pyridin‐4‐yl)‐2‐methoxy benzene sulfonic acid (SDAM), and 4,4′‐diaminodiphenyl ether (ODA). Flexible, transparent, and tough membranes were obtained. Property study revealed that all the membranes displayed high thermal stability with the desulfonation and decomposition temperature higher than 290 and 540°C, respectively, as well as good mechanical property with Young's modulus larger than 1.0 GPa, maximum strength (MS) on a scale of 60–80 MPa, and elongation at break (EB) ranged from 41.79 to 75.17%. More importantly, the new materials exhibited small water uptake and excellent dimensional stability with the highest sulfonated SPI‐80 showing the maximum water uptake of 36.1%, and maximum swollen ratio of Δt = 0.038 and Δl = 0.026, respectively (Δt and Δl stands for the thickness and diameter change of the film, respectively). The high water stability exhibited by the SPI films is attributed to the formation of inner salts and/or ionic crosslinking between the sulfonic acid and pyridine functional groups, which suppresses the water uptake ability of sulfonic acid and strengthened the interpolymer chain interactions. Thus, the excellent water stability, good thermal and mechanical properties, and the technologically applicable conductivity of SPI‐80 render this material attractive for proton exchange membrane (PEM) application. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Improved dispersion of clay platelets in poly(butylene terephthalate) nanocomposite by ring‐opening polymerization of cyclic oligomers: Effect of the processing conditions and comparison with nanocomposites obtained by melt intercalation
Authors: Berti C. , Binassi E. , Colonna M. , Fiorini M. , Zuccheri T. , Karanam S. , J. Brunelle D. 
Published: July 2009

AbstractPoly(butylene terephthalate) nanocomposites with organically modified montmorillonites have been prepared by in‐situ ring opening polymerization of PBT cyclic oligomers. High molecular weight polymers can be obtained by choosing the proper polymerization conditions and catalyst in very short polymerization time (10 min) and low temperature (205°C). A better dispersion of the clay and a consistently higher Mw have been obtained by this method respect to the standard melt intercalation approach, leading to improved thermo‐mechanical properties of the nanocomposite. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Thalidomide and misoprostol: Ophthalmologic manifestations and associations both expected and unexpected
Authors: Miller Marilyn T. , Ventura Liana , Strömland Kerstin 
Published: July 2009

AbstractThalidomide is a very potent teratogen capable of causing severe systemic malformations if the fetus is exposed during the sensitive period. Although structural anomalies of the eye can occur from thalidomide exposure, the most frequent eye complication is secondary to damage to the cranial nuclei in the brain stem, resulting in aberrant neurologic connections causing a condition of abnormal ocular movement, Duane syndrome. A less frequent anomalous neurologic complication is tearing when eating (paradoxical gustolacrimal tearing or “crocodile tears”) or lack of emotional tearing. The involvement of the 6th and 7th cranial nerves, often seen together in the thalidomide‐affected individual, is also characteristic of Möbius syndrome/sequence. This syndrome usually occurs sporadically, but characteristic findings of this condition have also been observed in South American children who were born after an unsuccessful attempt to induce abortion with the prostaglandin drug misoprostol (Cytotec©). Aberrant tearing also occurs in some individuals with Möbius syndrome. Autism spectrum disorder (ASD), an unexpected associated finding in a Swedish thalidomide study, is now also noted in Möbius studies, in patients both with and without exposure to misoprostol. Birth Defects Research (Part A) 2009. © 2009 Wiley‐Liss, Inc.
Inducible 70 kDa heat shock proteins protect embryos from teratogen‐induced exencephaly: Analysis using Hspa1a/a1b knockout mice
Authors: Barrier Marianne , Dix David J. , Mirkes Philip E. 
Published: July 2009

AbstractBACKGROUND:It is well known that a variety of teratogens induce neural tube defects in animals; however, less is known about proteins that play a role in protecting embryos from teratogen‐induced neural tube defects. Previously, our laboratory has shown that embryos overexpressing the 70‐Da heat shock proteins (HSPs) Hspa1a and Hspa1b were partially protected from the deleterious effects of exposure to hyperthermia in vitro.METHODS:In the present studies, we have used a transgenic mouse in which both of the stress‐inducible HSPs Hspa1a and Hspa1b were deleted by homologous recombination. Time‐mated Hspa1a/a1b‐/‐ (KO) and wildtype (WT) mice were exposed to hyperthermia in vivo on gestational day 8.5.RESULTS:Results show that 52% of the gestational day 15 fetuses from KO litters were exencephalic, whereas only 20% of WT fetuses were affected. In addition, 6% of treated KO fetuses also exhibited eye defects (microphthalmia and anopthalmia), defects not observed in WT fetuses exposed to hyperthermia. Lysotracker red staining and caspase‐3 enzyme activity were examined within 10 hours after exposure to hyperthermia, and significantly greater levels of apoptosis and enzyme activity were observed in the KO embryos compared with WT embryos.CONCLUSIONS:These results show that embryos lacking the Hspa1a and Hspa1b genes are significantly more sensitive to hyperthermia‐induced neural tube and eye defects, and this increased sensitivity is correlated with increased amounts of apoptosis. Thus, these results also suggest that Hspa1a and Hspa1b play an important role in protecting embryos from hyperthermia‐induced congenital defects, possibly by reducing hyperthermia‐induced apoptosis. Birth Defects Research (Part A) 2009. © 2009 Wiley‐Liss, Inc.
Neuromuscular synapse
Authors: Goodsell David S. 
Published: July 2009

AbstractDiverse biological data may be used to create illustrations of molecules in their cellular context. I describe the scientific results that support a recent textbook illustration of the neuromuscular synapse. The image magnifies a portion of the synapse at one million times, showing the location and the form of individual macromolecules. Results from biochemistry, electron microscopy, and X‐ray crystallography were used to create the image.
Making ordered DNA and protein structures from computer‐printed transparency film cut‐outs
Authors: Jittivadhna Karnyupha , Ruenwongsa Pintip , Panijpan Bhinyo 
Published: July 2009

AbstractInstructions are given for building physical scale models of ordered structures of B‐form DNA, protein α‐helix, and parallel and antiparallel protein β‐pleated sheets made from colored computer printouts designed for transparency film sheets. Cut‐outs from these sheets are easily assembled. Conventional color coding for atoms are used for both types of biopolymers. Arrows facilitate following chain direction for the polypeptides. For DNA, the 5′ to 3′ direction is guided by a 5′ phosphate group and a free hydroxyl group. Important chiral centers, for example, α‐carbon, deoxyribose C1′, are easily made. The main advantages of this version of DNA are the proportional major and minor grooves as in the actual molecule. More importantly, because of transparency of the film one can see successive base‐pair stacking very clearly and also the sense of relative base‐pair rotation. Because of the introduction of two central metal wire axes, the model of B‐form DNA can be twisted to give a rather good representation of A‐form and even a semblance of a left‐handed helix. The models of secondary structure of protein allow a better insight into the axial alignment of side chains, the formation of hydrogen bond, the handedness of the α‐helix, and the backbone connection between the β‐strands. Students taught by these models understand 3D features of the biopolymers better than from textbook illustrations, computer graphic representations, and even common paper and plastic versions.
Analysis of a p53 mutation associated with cancer susceptibility for biochemistry and genetic laboratory courses
Authors: Soto‐Cruz Isabel , Legorreta‐Herrera Martha 
Published: July 2009

AbstractWe have devised and implemented a module for an upper division undergraduate laboratory based on the amplification and analysis of a p53 polymorphism associated with cancer susceptibility. First, students collected a drop of peripheral blood cells using a sterile sting and then used FTA cards to extract the genomic DNA. The p53 region is then PCR amplified, and the PCR products are digested with the BstUI enzyme to detect the 72 codon polymorphism. Polyacrylamide gel electrophoresis is used to resolve the PCR products, and the results are statistically analyzed in the context of human population genetics. Blood samples in FTA cards were also collected from 50 women to detect the mutation in a wide range of ages and assess its relationship to familial cancer susceptibility. This module enables students to use materials and methods that are routinely used by scientific researchers to analyze polymorphisms. Therefore, it can be used for laboratory exercises in traditional biochemistry curricula as well as in the growing field of genomic science and education.
Application of polyethyleneimine‐modified scaffolds to the regeneration of cartilaginous tissue
Authors: Kuo Yung‐Chih , Ku I‐Nan 
Published: July 2009

AbstractIn this study, we analyzed the physicochemical and biophysical properties of three‐dimensional scaffolds modified using polyethyleneimine (PEI) and applied these scaffolds to the cultivation of bovine knee chondrocytes (BKCs). PEI was crosslinked in the bulk or on the surface of the ternary scaffolds comprising polyethylene oxide, chitin and chitosan. The results revealed that when the concentration of PEI was less than 300 μg/mL, the cytotoxicity of a scaffold was on the same order in the two method of modification. An increase in the concentration of PEI favored the adhesion of BKCs. When the amount of PEI in scaffolds is fixed, the surface‐modified scaffolds exhibited a higher adhesion efficiency of BKCs than the bulk‐modified scaffolds. For the regeneration of cartilaginous components, a higher amount of PEI in a scaffold yielded larger amounts of proliferated BKCs, secreted glycosaminoglycans, and produced collagen. In addition, the formation of neocartilage in the surface‐modified scaffolds was more effective than that in the bulk‐modified scaffolds. These tissue‐engineered scaffolds, modified by an appropriate concentration of PEI, can be potentially applied to cartilage repair in clinical trials. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
Soyprotein fibers with high strength and water stability for potential medical applications
Authors: Reddy Narendra , Yang Yiqi 
Published: July 2009

AbstractFibers with mechanical properties and water stability suitable for tissue engineering have been developed from soyproteins. Proteins are biocompatible and biodegradable and are preferred over synthetic polymers for medical applications. Although plant proteins are abundant and inexpensive and can be made into various types of scaffolds, very few attempts have been made to understand the suitability of using plant proteins for medical applications, especially as fibrous substrates for tissue engineering. So far, it has not been able to obtain good quality soyprotein fibers without using toxic crosslinking agents or blending soyprotein with synthetic polymers. In this research, we have developed 100% soyprotein fibers with good strength and water stability without using any external crosslinking agents. The soyprotein fibers have better wet strength than collagen fibers and are conducive to the attachment, growth, and proliferation of mouse fibroblasts. Fibers are better substrates than films for growth and orientation of cells and are therefore preferable for tissue engineering applications. Soyprotein fibers show good potential to be novel biomaterials with properties suitable for tissue engineering and other medical applications. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009