bluuebunny/crossref_metadata_2025 huggingface dataset:
Manifestations of muscle fatigue in baseball pitchers: a systematic review
Authors: Birfer Richard , Sonne Michael WL , Holmes Michael WR
Published: July 2019

Background

Fatigue in baseball pitchers is a process linked to lowered physical and mental performance, injury, and changes in kinematics. Numerous studies have associated fatigue with overuse, high ball velocities, lack of rest time, poor mechanics, and degree of self-satisfaction. The aim of this study was to systematically review the literature to identify a theoretical framework for the relationship between outcomes and the manifestation of fatigue on baseball pitching. The synthesized data may identify areas requiring further research.

Methodology

This protocol was registered with PROSPERO (ID: CRD42018114194). SPORTDiscus, Medline, PubMed, Cochrane Database of Systematic Reviews, and Google Scholar were searched, using keywords such as fatigue in pitchers and changes in kinematics (e.g., pitching mechanics, valgus elbow torque), performance (e.g., pitch count, pitch type), and injury (e.g., pain, elbow, and shoulder soreness). Three reviewers independently screened the articles, selected relevant literature based on abstract eligibility, and assessed the methods described therein for final inclusion.

Results

A total of 31,860 articles were screened for eligibility and 25 articles were included for the review. The selected articles included epidemiological, longitudinal, experimental, conference papers, and crossover laboratory studies. Evidence extracted from the 25 studies demonstrates a relationship between fatigue in baseball pitching, and three overarching outcomes: changes in kinematics, a decrease in performance, and an increase in injury risk.

Conclusions

Findings show that a co-dependence between changes in kinematics and a decrease in performance, which stems from central and peripheral fatigue, is a contributing factor of injury in baseball pitchers. A large percentage of baseball pitchers exhibit pain or soreness in either their elbow or shoulder, or both at some point in a season. Initially, kinematic changes occur that could maintain performance, but may increase joint and tissue loading. Performance decreased with elevated pitch counts and innings thrown, and pitching further into games or the season. Evidence was found to be consistent across all studies; however, more work is needed in the area of fatigue as an injury mechanism during pitching. With a proof of concept established, the prevention of negative outcomes associated with fatigue must be the focus of future research and performance should not be the only criteria.
Self-efficacy and enjoyment of physical activity in children: factorial validity of two pictorial scales
Authors: Morano Milena , Bortoli Laura , Ruiz Montse C. , Vitali Francesca , Robazza Claudio
Published: July 2019

Background

Self-efficacy and enjoyment are two main constructs proposed within many motivational theories in any human endeavor, sport and physical activity included.

Methods

The purpose of this study was to examine the factor structure of two pictorial scales measuring self-efficacy and enjoyment levels in a sample of 14,035 Italian schoolchildren (7,075 boys and 6,960 girls, 6- to 7-year-olds). An important feature of the two scales is that they are in a pictorial format in order to prompt a straightforward understanding in children. The whole sample was randomly split in two subsamples according to gender and age and the factor structure of the measures was examined across subsamples.

Results

Data were subjected to confirmatory factor analysis, which yielded satisfactory fit indices on the measures of both subsamples. Overall findings supported the single factor structure of the scales, which can be easily administered to 6- to 7-year-old children to assess two relevant psychological constructs in physical education.
Quality Assessment of Bread from Wheat, Water Yam and Soybean Flours
Authors: Ochelle P. O. , Ikya J. K. , Ameh C. O. , Gbaa S. T.
Published: July 2019

The physicochemical and sensory evaluation of bread from the composite of wheat, water yam and soybean flours were determined. Five bread samples were produced from the proportion of wheat/water yam/soybean flours as 80%:10%:10% (B), 75%:15%:10% (C), 70%:20%:10% (D), 65%:25%10% (E) and 100% wheat was the control sample (A). The moisture, crude protein, fiber and ash increased (p≤0.05) significantly while the carbohydrate and fat content decreased (p≤0.05) significantly with corresponding increase in the percentage of the composite flour from 10-25% for water yam flour at constant 10% soybean level. The result of the physical properties showed that there was a significant difference in all the physical parameters except loaf weight which didn’t increased (p≥0.05) significantly with increased addition of water yam flour at constant soybean level. The result of the sensory analysis showed there were significant differences in all the sensory scores. However, consumers preferred the bread from the composite flours of 20% substitution for both water yam and soybean flours.
Assessment of Sub Chronic Toxicity of Sonchus cornutus in Rats
Authors: Farah Hayat Mahgoub , Hussein Abdel Rahim Mohamed El , Khalid Hassan Elsubki , Osman Halima Mohamed
Published: July 2019

Aim: To assess the toxicity of the aqueous extract of Sonchus cornutus in Wistar albino rats.

Methodology: The aqueous extract of Sonchus cornutus aerial part was administered orally to rats in group 2, 3 and 4 at a dose of 50, 500 and 2000 mg/ kg, respectively for four weeks whereas, group 1 was kept as a control. The animals were observed daily for clinical signs and mortality. Weekly, the weights of the animals were recorded, and blood samples were collected for haematological and biochemical analysis. Specimens of Liver and kidney were kept in 10% formalin for histopathology.

Results: The results revealed that all the animals in the four groups survived. The extract had no adverse effects on haematology, biochemistry and histology of rats at doses of 50 and 500 mg/ kg. But dose 2000 mg/kg proved to have significant alteration in White blood cells (WBCs), Red blood cells (RBCs), Haemoglobin (Hb) and Packed cell volume (PCV). In addition, total protein, albumin, urea, creatinine, Alanin Transaminase (ALT), Asparate Transaminase (AST) were significantly (P<0.05) changed. These findings correlated with the histopathological changes on liver and kidney.

Conclusion: The highest dose of S. cornutus aqueous extract (2000 mg/kg) was not fatal, but may have some toxic effects on liver and kidney.
Synthesis Spectroscopy and Computational Studies of Manganese (II) Complexes Incorporating (N,O)(O,O`) Ligands and Their Biological Activity
Authors: Abokhater Rania Ahmad , Ashoor Salem Eltuhami , Gadir Suad A.
Published: July 2019

Manganese (II) complexes were synthesized via the reaction equimolar quantity of Manganese(II) chloride-hydrate (MnCl2.6H2O) with Chiral saccharides such {(OH)5(CH2)(C5H5)O} or {(OH)6(CH2)(C5H5)O} and (C9H7NO) as secondary ligands [Mn(C9H7NO){(OH)5(CH2)(C5H5)O}]Cl2 (C1), [Mn(QH){(OH)6(CH2)(C5H5)O}]Cl2 (C2), respectively where (C9H7NO) is 8-hydroxyquinoline, {(OH)5(CH2)(C5H5)O} Dextrose (Dex), {(OH)6(CH2)(C5H5)O} fructose (fru). Theses complexes were characterized by UV-vis, IR spectroscopy, tandem mass spectrometry and elemental analysis.

The complexes have been found to have square planer geometry as the optimization method. The molecular geometries obtained from XRD data.

The pre-optimized to standard convergence criteria using the basis Minimize Energy to Minimum.

The isolated compounds were screened for its antibacterial activity against six standard human pathogens (Staphylococcus aureus, Streptococcus spp., Escherichia coli, Klebsiella spp., Psuedomones spp. and Protues spp.) and the results were obtained. About 10 to 70% for complex (C1) and about 10 to 60% for complex (C2) of the activity.
Experimental and Theoretical Evaluation of the Structure and Properties of New Stannyl Complexes of Pyridine Amide Ligands
Authors: Thomas Raji , Pardasani Pushpa
Published: July 2019

Aims: Penta and tetra coordinated stannyl derivatives of N, N'-Bis(2-pyridyl)pyridine-2,6-dicarboxamide (H2L) and N-(pyridine-2-yl)picolinamide (HL1) have been synthesized. The structure of the complexes has been well established by Sn119 NMR and computational studies (GAUSSIAN 03 suit of programs). MESP and NBO studies have been carried out to understand different binding modes and properties of the complexes as well as ligands. The relative bond strengths have been estimated using the Wiberg bond index analysis.

Study Design:  Experimental and computational.

Place and Duration of Study: Department of Chemistry, University of Rajasthan, Jaipur, 2014.

Methodology: The structure of the complexes has been analyzed by IR and NMR. Computational studies (GAUSSIAN 03 suit of programs) have been used to elucidate the structure of the newly synthesized complexes.

Results: 119Sn NMR showed a pentacoordinate range for diamide complexes indicating coordination through the nitrogen of central pyridine ring in addition to amide nitrogens and tetracoordinate range for monoamide complexes confirming the formation of the products. The bonding properties have been confirmed by the computational calculations.

Conclusion: A series of dialkyl/diphenyl and trialkyl/triphenyl derivatives of organo tin complexes containing amide functionality have been synthesized and their structural characterizations performed by different spectral techniques and computational analysis.
Isolation and Characterization of Phosphate Solubilising Rhizobia Nodulating Wild Field Pea (Pisum sativum var. abyssinicum) from Southern Tigray, Ethiopia
Authors: Gebremedhin Aklil , Assefa Fassil , Argaw Anteneh
Published: July 2019

Hypothesis: Phosphorus is the second limiting nutrients next to nitrogen as well as the least mobile element in the soil. This nutrient is one of the major constraints for low productivity of wild field pea in the study site. Hence, the development of environmental friendly and economically accepted to subsistent farmer is undeniably important.

Aims: This experiment was initiated to isolate and characterize inorganic phosphate solubilizing rhizobia from root nodules of field pea (Pisum sativum var. abyssinicum) were characterized for their solubilisation ability on Pikovaskaya liquid and solid media.

Study Design: Laboratory experimental design was used.

Place and Duration of Study: Field pea root nodules were collected from Southern Tigray and the study was carried out between October, 2015 and June, 2016 at Haremaya University soil microbiology laboratory.

Methodology: The presumptive test, qualitative and quantitative phosphate solubilisation of isolates was done in triplicates using the standard procedures. Authentication of the isolates was made using autoclaved and sterilized river sand in pot experiment.

Results: The current results revealed that all isolates were gram negative, failed to grow on peptone glucose agar, ketolactose test and did not absorb congo-red upon incubation period. It also showed that phosphate solubilisation index of root nodulating bacteria on in vitro Pikovskaya’s agar medium varied from 1.54 to 2.70. Inorganic phosphate solubilisation in broth medium dissolved insoluble Ca3 (PO4)2 was within the range of 16.59-23.95 mg plant-1 with pH drop from 7.01 to 5.33. Among the tested rhizobia isolates, HUDRI-8 and HUDRI-25 was found to be highest phosphate solubilisation compared to the remaining isolates, served as efficient phosphate solubilizers and could be used for further test under field condition.

Conclusion: Finally, the selected isolates which are effective in N2 fixation and able to solubilise inorganic P were found to be effective in promoting nodulation and plant growth under greenhouse condition.
Knowledge, Uptake and Barriers to Pap Smear Test among Female Workers in the Rivers State University Teaching Hospital, Nigeria
Authors: Awoyesuku P. A. , Altraide B. O. A. A. , MacPepple D. A.
Published: July 2019

Background: Early screening for cervical cancer is a key intervention in reduction of maternal deaths. Health care workers have a significant role to improve cervical cancer screening practice among women. Their attitude and practice to such an issue might positively or negatively influence people they come into contact with.

Objective: To determine the knowledge, uptake and barriers to Pap smear test among female workers in the Rivers State University Teaching Hospital.

Methodology: A hospital-based cross-sectional study was conducted between September and November 2015. A structured and pre-tested questionnaire was used to collect data from 265 female hospital workers on socio-demographic characteristics, knowledge of Pap smear, attitude towards, as well as utilization of Pap smear test. The data obtained were analyzed using SPSS version 20.0.

Results: Of the 265 respondents, 237 (89.4%) were aware of Pap smear while 28 (10.6%) had no knowledge; of those that had knowledge only 40 (16.9%) had Pap smear test done at least once previously. There is significant difference in the knowledge of Pap smear among the professionals and those with tertiary education. Common sources of information about Pap smear were Books (58.2%) and Medical Workers (50.6%). Most common reason for not wanting to be screened was No interest (43.6%).

Conclusion: Although the knowledge of Pap smear is high, the uptake is low among hospital workers. To improve utilization, public health education on the need for health workers to take up screening is crucial as it will impact positively on the general populace.
Assessment of Antiplasmodial Activity and Toxicity of Crude Extracts and Isolated Compounds from Oncoba spinosa (Flacourtiaceae)
Authors: Philip Kodi , Cheplogoi Peter Kiplagat , Elizabeth Mwangi Muthoni , Hoseah M. Akala , Langat Moses K.
Published: July 2019

Aims: The medicinal plant Oncoba spinosa is used by the local communities in Butebo County in Eastern Uganda for treatment of malaria and other diseases. In vitro antiplasmodial activities of the crude extracts and isolated compounds were screened against chloroquine sensitive 3D7 and resistant Dd2 strains. In vivo acute toxicity of the extracts and structure elucidation were also determined in the study.

Experimental: Crude extracts of: n-hexane, dichloromethane, ethyl acetate and methanol were prepared. Isolation and purification of these extracts were done using chromatographic techniques which consisted of column and thin layer chromatography. The structures were elucidated on the basis of spectroscopic evidence. In vitro antiplasmodial activity was performed on chloroquine sensitive 3D7 and resistant Dd2 strains of Plasmodium falciparum using SYBR Green 1 assay technique. Lorke’s method of acute toxicity was used to determine the in vivo acute toxicity of the crude extracts in mice.

Results: The root ethyl acetate crude extract had highest antiplasmodial activity of IC50:4.69 ± 0.01 µg/mL and 3.52 ± 0.02 µg/mL against 3D7 and Dd2 strains respectively while the remaining three were inactive against both strains of Plasmodium. Isolation resulted in the identification of three known compounds which included: β-sitosterol, benzoic acid and chaulmoogric acid. Among the tested compounds β-sitosterol showed the highest activity of IC50 3D7: 5.51 µM. Dichloromethane and hexane extracts were non-toxic with LD50 > 5000 mg/kg while the EtOAc and MeOH extracts were slightly toxic with LD50 of 547.72 mg/kg. Statistically significance existed between the antiplasmodial activity of the crude extracts and compounds when compared with the controls at (p < 0.05). Extracts and compounds exerted a significant (P < 0.05) decrease in antiplasmodial activity compared to the positive controls.

Conclusion: The findings confirm the ethnobotanical use of O. spinosa by the local communities in Butebo County for the treatment of malaria. The results also suggest that the crude extract of this plant is safe and possesses antimalarial activity which can be used as a basis for in vivo and clinical studies to be done. Therefore the plant can offer a potential drug lead for developing a safe, effective and affordable antimalarial.
Production of Biomass Briquettes Using Coconut Husk and Male Inflorescence of Elaeis guineensis
Authors: Lawal O. J. , Atanda T. A. , Ayanleye S. O. , Iyiola E. A.
Published: July 2019

The decreasing availability of fuel wood coupled with the increasing prices of kerosene and cooking gas in Nigeria has drawn attention on the need to consider alternative sources of energy for domestic and industrial use in the country. The study was undertaken to evaluate the combustion properties (percentage volatile matter, percentage ash content, percentage fixed carbon, heating value) of briquette produced from coconut husk and male inflorescence of Elaeis guineensis. The experiment was laid down using the Randomized Complete Block Design (RCBD). The study involves three particle sizes (2 mm each) of coconut husk, male inflorescence of oil palm tree and cassava starch used as binder. The coconut husk and male inflorescence of Elaeis guineensis were varied into (25:30:40:50:60) respectively and bound together with starch at same ratio. Proximate analysis was carried out to determine the constituent of the briquettes which include ash content, percentage fixed carbon, percentage volatile matter and experimental test to determine the heating value was also determined. All processing variables in this study were significantly different except for heating value at P>0.05. From the result of the percentage ash content, briquette produced from coconut husk, male inflorescence and starch at (20:20:60) has the least fixed carbon (6.5%) with better performance. The highest percentage volatile matter 74.6% was obtained from coconut husk, male inflorescence and starch at (20:20:60) while low fixed carbon (18.8%) was obtained from male inflorescence and starch at (60:40). In conclusion, large quantities of wastes generated in terms of coconut husk and male inflorescence which are disposed indiscriminately can be utilized to produce briquette with enhanced performance.
School Type and Leadership Pattern of Principals as Predictors of Science Teachers’ Job Performance in Rivers State Nigeria
Authors: Furo Pepple Tamunosisi , Ndimele Stanley
Published: July 2019

This study, investigated the effect of school type (public and private) and leadership pattern of principal on teachers' job performance in Rivers State Nigeria. The design for the study was survey.  The target population for this study comprises of all the Senior Secondary School Three (SS 3) students and their teachers in public and private Schools in Rivers State Nigeria. Simple random sampling technique was used to select 370 'respondents (60 teachers and 310 students) and, stratified random sampling was used to select twelve (12) secondary schools. Data were collected using Students' Perception of Teachers' Job Performance Questionnaire (SPTJPQ) and Teachers' Perception of School Type and Principals' Leadership Style Questionnaire (TPSTPLSQ) with 0.74 and 0.92 reliability coefficients respectively using Cronbach Alpha statistic. Three research questions guided the study, and Pearson Product Moment Correlation and Multiple Regressions were the statistical tools used for data analysis with the aid of Statistical Package for Social Science (SPSS) version 20. This study showed relationships among and between variables in terms of their direction and strength. All the variables considered in this study have relationships with the criterion variable at varying strengths. While the school type (r = -.008 p>0,05), autocratic leadership style (r = -.112 p<0.05) and laissez faire leadership style (r = -.008 p>0.05) are negatively correlated; only the autocratic leadership style had significant relationship with the criterion. The study therefore, concluded that all the variables of the study are correlated at varying strength and different direction.
Quantitative Structure Activity Relationship of New Isatin Analogues for Design New Compounds as Anti-breast Cancer
Authors: Khabnadideh Soghra , Sabet Razieh , Naghz Hasti Pour , Divar Masoumeh
Published: July 2019

Breast cancer is the most common diagnosed cancer and the leading cause of related death in woman across the world. Nowadays, there are many effective chemotherapeutic agents used in the treatment of breast cancer, however due to the high side effects of these drugs, there is still an urgent need to develop new drugs for battle the disease. Computational chemistry is unique method in drug discovery which reduce cost. In this study 105 molecules were subjected to quantitative structure-activity relationship analysis to find the structure requirements for ligand binding. Then their structures were drowning in Hyperchem and also optimized, the structural invariants used in this study were those obtained from whole molecular structures: by both hyperchem and dragon. Four chemometrics method including MLR, FA-MLR, PCR and GA-PLS were employed to make connection between structural parameters and cytotoxic effects. GA-PLS showed Chemical, Topological, Randic molecular, Charge, 3D-Morse, Functional, Atom-centeredindices to be the most significant parameters on cytotoxic activity. The result of FA-MLR analysis revealed the effects of Chemical, Atom-centered, Galvez and Functional on the cytotoxic activity too. A comparison between the different statistical methods employed indicated that GA-PLS represented superior results and it could explain and predict 72% and 80% variances in the PIC50 data, respectively.
Evolutionary Origin of Teeth
Authors: Rücklin Martin , Donoghue Philip CJ
Published: July 2019

Teeth and jaws have been widely perceived as key innovations underpinning the adaptive radiation and the evolutionary success of jawed vertebrates. However, the origin, evolution and developmental evolution of teeth are all the subject of controversy. There are three competing hypotheses that are more or less well supported by the available data: (1) the ‘outside‐in’ hypothesis which contends that odontogenic competence spread from the external dermis to the oropharynx – the traditional hypothesis based on the observation that teeth and scales exhibit common patterns of development that extend to the molecular genetic level, combined with evidence that scales appear before teeth within phylogeny; (2) the ‘inside‐out’ hypothesis that teeth and scales evolved independently, based on the observation that some jawless scale‐covered vertebrates also possess oro‐pharyngeal scales, and (3) the ‘inside and out’ hypothesis which is effectively agnostic on the question. The available evidence supports an origin of teeth through extension of odontogenic competence from the external dermis to the oropharynx.

Key Concepts

‘Outside‐in’ hypothesis argues for an evolution of teeth after the evolution of jaws from ectodermal epithelium, based on the observation that teeth and scales are considerably similar in their development and morphology.

‘Inside‐out’ hypothesis argues for an evolution of teeth before jaws from an endodermal epithelium, based on the assumption that teeth and scales are considerably different and have no common origin.

‘Inside and out’ hypothesis argues for a deep homology and ancient gene regulatory network for nonmineralised (taste buds) and mineralised appendages (scales and teeth).

Odontodes are a descriptive observation defined as hard tissue structures that develop in a single papilla, consist of dentine or dentinous tissue and frequently a superficial enameloid layer.

Whole genome duplications as drivers of vertebrate evolution enabling mutations ultimately resulting in the evolution of novelties considered as key‐innovations, e.g. jaws and teeth.

Phylogenetic congruence is a test of an evolutionary scenario with cladistics and a well‐supported phylogeny.
Why should we try to think like scientists? Scientific reasoning and susceptibility to epistemically suspect beliefs and cognitive biases
Authors: Čavojová Vladimíra , Šrol Jakub , Jurkovič Marek
Published: July 2019

This paper examines whether scientific reasoning skills predict people's susceptibility to epistemically suspect beliefs and cognitive biases. We used the recently developed Scientific Reasoning Scale (SRS) because it measures the ability to read and evaluate scientific evidence. Alongside the SRS, 317 participants aged 18–30 years completed measures of thinking dispositions and cognitive ability to ascertain whether the SRS contributes specifically to susceptibility to epistemically suspect beliefs and cognitive biases. Scientific reasoning correlated positively with dispositions towards analytic thinking and cognitive ability and negatively with dogmatism, epistemically suspect beliefs, and susceptibility to cognitive biases. Most importantly, it emerged as a significant predictor, contributing to susceptibility to both cognitive biases and epistemically suspect beliefs over and above the other cognitive predictors. These results provide the first empirical evidence that scientific reasoning ability is an important factor in protecting against epistemically suspect beliefs and in aiding better decision making among the non‐scientific population.
Highly Flexible and Stretchable Nanowire Superlattice Fibers Achieved by Spring‐Like Structure of Sub‐1 nm Nanowires
Authors: Zhang Simin , Lin Haifeng , Yang Haozhou , Ni Bing , Li Haoyi , Wang Xun
Published: July 2019

Conventional inorganic nanowire (NW) fibers are usually not stretchable and elastic, which may limit their practical applications. Inspired by the similarity between inorganic sub‐1 nm NWs and polymer chains in dimension, and helical spring‐like structure of cellulose in cherry bark, highly flexible and stretchable NW superlattice fibers composed of sub‐1 nm GdOOH NWs are fabricated. The NW fibers could be twined, bent, twisted, and tied without any damage. When the strain is less than 10%, the fibers present elastic deformation. The elongation at break of the fibers usually reaches ≈40–50% and the highest elongation could reach ≈86%. Excellent flexibility and stretchability of the NW fibers are attributed to the well‐aligned spring‐like NWs assembled superlattice, which are demonstrated by scanning electron microscopy tests, synchrotron small‐angle X‐ray scattering, and obvious birefringence. Moreover, NW‐nanoparticle (NP) fibers are fabricated, inspired by inorganic nanoparticle–reinforced polymers. The strength is improved compared with the NW fibers. Based on this work, it is possible to fabricate multifunctional, flexible, and stretchable inorganic NW materials composed of different inorganic sub‐1 nm NWs, which may be useful in practical applications.
An Injectable Strong Hydrogel for Bone Reconstruction
Authors: Zhao Yanran , Cui Zhiyong , Liu Bingchuan , Xiang Junfeng , Qiu Dong , Tian Yun , Qu Xiaozhong , Yang Zhenzhong
Published: July 2019

For treating bone defects in periarticular fractures, there is a lack of biomaterial with injectable characteristics, tough structure, and osteogenic capacity for providing a whole‐structure support and osteogenesis in the defect area. An injectable hydrogel is an ideal implant, however is weak as load‐bearing scaffolds. Herein, a new strategy, i.e., an in situ formation of “active” composite double network (DN), is raised for the preparation of an injectable strong hydrogel particularly against compression. As a demonstration, 4‐carboxyphenylboronic acid grafted poly(vinyl alcohol) (PVA) is crosslinked using calcium ions to provide a tough frame while bioactive glass (BG) microspheres are associated by poly(ethylene glycol) to obtain an interpenetrated inorganic network for reinforcement. The injected PVA/BG DN hydrogel gains compressive strength, modulus, and fracture energy of 34 MPa, 0.8 MPa, and 40 kJ m−2, respectively. Then, the properties can be “autostrengthened” to 57 MPa, 2 MPa, and 65 kJ m−2 by mineralization in 14 days. In vivo experiments prove that the injected DN hydrogel is more efficient to treat femoral supracondylar bone defects than the implanted bulk DN gel. The work suggests a facile way to obtain a strong hydrogel with injectability, cytocompatibility, and tailorable functionality.
Intrinsic Conductance of Domain Walls in BiFeO3
Authors: Zhang Yi , Lu Haidong , Yan Xingxu , Cheng Xiaoxing , Xie Lin , Aoki Toshihiro , Li Linze , Heikes Colin , Lau Shu Ping , Schlom Darrell G. , Chen Longqing , Gruverman Alexei , Pan Xiaoqing
Published: July 2019

Ferroelectric domain walls exhibit a number of new functionalities that are not present in their host material. One of these functional characteristics is electrical conductivity that may lead to future device applications. Although progress has been made, the intrinsic conductivity of BiFeO3 domain walls is still elusive. Here, the intrinsic conductivity of 71° and 109° domain walls is reported by probing the local conductance over a cross section of the BiFeO3/TbScO3 (001) heterostructure. Through a combination of conductive atomic force microscopy, high‐resolution electron energy loss spectroscopy, and phase‐field simulations, it is found that the 71° domain wall has an inherently charged nature, while the 109° domain wall is close to neutral. Hence, the intrinsic conductivity of the 71° domain walls is an order of magnitude larger than that of the 109° domain walls associated with bound‐charge‐induced bandgap lowering. Furthermore, the interaction of adjacent 71° domain walls and domain wall curvature leads to a variation of the charge distribution inside the walls, and causes a discontinuity of potential in the [110]p direction, which results in an alternative conductivity of the neighboring 71° domain walls, and a low conductivity of the 71° domain walls when measurement is taken from the film top surface.
Ligand‐Installed Nanocarriers toward Precision Therapy
Authors: Mi Peng , Cabral Horacio , Kataoka Kazunori
Published: July 2019

Development of drug‐delivery systems that selectively target neoplastic cells has been a major goal of nanomedicine. One major strategy for achieving this milestone is to install ligands on the surface of nanocarriers to enhance delivery to target tissues, as well as to enhance internalization of nanocarriers by target cells, which improves accuracy, efficacy, and ultimately enhances patient outcomes. Herein, recent advances regarding the development of ligand‐installed nanocarriers are introduced and the effect of their design on biological performance is discussed. Besides academic achievements, progress on ligand‐installed nanocarriers in clinical trials is presented, along with the challenges faced by these formulations. Lastly, the future perspectives of ligand‐installed nanocarriers are discussed, with particular emphasis on their potential for emerging precision therapies.
Homogeneous Freestanding Luminescent Perovskite Organogel with Superior Water Stability
Authors: Zhang Yucheng , Zhao Yusen , Wu Dong , Xue Jingjing , Qiu Yu , Liao Michael , Pei Qibing , Goorsky Mark S. , He Ximin
Published: July 2019

Metal‐halide perovskites have become appealing materials for optoelectronic devices. While the fast advancing stretchable/wearable devices require stability, flexibility and scalability, current perovskites suffer from ambient‐environmental instability and incompatible mechanical properties. Recently perovskite−polymer composites have shown improved in‐air stability with the protection of polymers. However, their stability remains unsatisfactory in water or high‐humidity environment. These methods also suffer from limited processability with low yield (2D film or beads) and high fabrication cost (high temperature, air/moisture‐free conditions), thereby limiting their device integration and broader applications. Herein, by combining facile photo‐polymerization with room‐temperature in‐situ perovskite reprecipitation at low energy cost, a one‐step scalable method is developed to produce freestanding highly‐stable luminescent organogels, within which CH3NH3PbBr3 nanoparticles are homogeneously distributed. The perovskite‐organogels present a record‐high stability at different pH and temperatures, maintaining their high quantum yields for > 110 days immersing in water. This paradigm is universally applicable to broad choices of polymers, hence casting these emerging luminescent materials to a wide range of mechanical properties tunable from rigid to elastic. With intrinsically ultra‐stretchable photoluminescent organogels, flexible phosphorous layers were demonstrated with > 950% elongation. Rigid perovskite gels, on the other hand, permitted the deployment of 3D‐printing technology to fabricate arbitrary 2D/3D luminescent architectures.
Highly Efficient Light Emitting Diodes Based on In Situ Fabricated FAPbI3 Nanocrystals: Solvent Effects of On‐Chip Crystallization
Authors: Zhang Xin , Han Dengbao , Wang Chenhui , Muhammad Imran , Zhang Feng , Shmshad Ali , Xue Xulan , Ji Wenyu , Chang Shuai , Zhong Haizheng
Published: July 2019

The in situ fabricated perovskite nanocrystals (PNCs) obtained through spin‐coating a precursor solution are suitable candidates to achieve efficient perovskite light emitting diodes (PeLEDs). In this work, the solvent effects of on‐chip crystallization are investigated by correlating the nucleation and growth process of in situ fabricated formamidinium lead iodide (FAPbI3) nanocrystals with their optical and electronic properties. The FAPbI3 nanocrystals obtained from a precursor solution in γ‐butyrolactone (GBL) are smaller than those obtained from N,N‐dimethylformamide and dimethyl sulfoxide, and the relatively weak coordination between GBL and the precursor molecules enables reduced defect states in the resulted PNCs with enhanced photoluminescence properties. A modified LaMer model is proposed to describe the solvent effects in the on‐chip crystallization process. Based on these understandings, red emissive FA0.87Cs0.13PbI3 nanocrystal films with absolute photoluminescence quantum yields up to 70% are realized. Finally, an efficient PeLED with maximum luminance of 218 cd m−2 and peak external quantum efficiency of 15.8% is achieved with good reproducibility.
Insight of a Phase Compatible Surface Coating for Long‐Durable Li‐Rich Layered Oxide Cathode
Authors: Hu Sijiang , Li Yu , Chen Yuhua , Peng Jiming , Zhou Tengfei , Pang Wei Kong , Didier Christophe , Peterson Vanessa K. , Wang Hongqiang , Li Qingyu , Guo Zaiping
Published: July 2019

Li‐rich layered oxides (LLOs) can deliver almost double the capacity of conventional electrode materials such as LiCoO2 and LiMn2O4; however, voltage fade and capacity degradation are major obstacles to the practical implementation of LLOs in high‐energy lithium‐ion batteries. Herein, hexagonal La0.8Sr0.2MnO3−y (LSM) is used as a protective and phase‐compatible surface layer to stabilize the Li‐rich layered Li1.2Ni0.13Co0.13Mn0.54O2 (LM) cathode material. The LSM is MnOM bonded at the LSM/LM interface and functions by preventing the migration of metal ions in the LM associated with capacity degradation as well as enhancing the electrical transfer and ionic conductivity at the interface. The LSM‐coated LM delivers an enhanced reversible capacity of 202 mAh g−1 at 1 C (260 mA g−1) with excellent cycling stability and rate capability (94% capacity retention after 200 cycles and 144 mAh g−1 at 5 C). This work demonstrates that interfacial bonding between coating and bulk material is a successful strategy for the modification of LLO electrodes for the next‐generation of high‐energy Li‐ion batteries.
Sinonasal quality‐of‐life outcomes after endoscopic endonasal skull base surgery
Authors: Bhenswala Prashant N. , Schlosser Rodney J. , Nguyen Shaun A. , Munawar Suqrat , Rowan Nicholas R.
Published: July 2019

Background

There are substantial gaps in our understanding of the influence of the endoscopic endonasal approach (EEA) for endoscopic skull base surgery on sinonasal‐specific quality of life (QOL) as well as the instruments available for assessment. Our primary objective in this study was to characterize postoperative changes in sinonasal QOL, specifically using the 22‐item Sino‐Nasal Outcome Test (SNOT‐22), with a secondary objective of delineating weaknesses in our current understanding of patient symptomatology after EEA for skull base surgery.

Methods

A comprehensive literature review was conducted using PubMed, CINAHL, Cochrane Library, and SCOPUS for studies reporting SNOT‐22 data pre‐ and postoperatively in patients who underwent EEA for skull base pathologies. Studies were limited to patients ≥18 years of age and excluded patients diagnosed with chronic rhinosinusitis (CRS).

Results

Nineteen unique studies with 27 separate data sets and a total of 1025 patients were used in this meta‐analysis. Overall SNOT‐22 scores statistically improved at the 6‐month (p = 0.0009) and 1‐year (p = 0.002) time‐points. Patients with preoperative SNOT‐22 scores ≥20 achieved postoperative improvements at 12‐week (p < 0.00001), 6‐month (p < 0.0001), 1‐year (p < 0.00001), and long‐term follow‐up (p < 0.0001). Patients with preoperative SNOT‐22 scores <20 remained stable and did not worsen postoperatively.

Conclusion

Patients undergoing EEA for skull base pathologies who have impaired sinonasal QOL preoperatively demonstrated significant postoperative QOL improvements. Those patients with relatively normal preoperative sinonasal QOL remained asymptomatic postoperatively. This study supports the need for development of a contemporary disease‐ and approach‐specific, validated QOL instrument for skull base pathologies.
The Dual‐Stereocontrol Mechanism: Heteroselective Polymerization of rac‐Lactide and Syndioselective Polymerization of meso‐Lactide by Chiral Aluminum Salan Catalysts
Authors: Hador Rami , Botta Antonio , Venditto Vincenzo , Lipstman Sophia , Goldberg Israel , Kol Moshe
Published: July 2019

We describe alkoxo‐aluminum catalysts of chiral bipyrrolidine‐based salan ligands that follow the dual‐stereocontrol mechanism wherein a given combination of stereogeneities at the metal site and the proximal center of the last inserted lactidyl (“match”) is active towards lactide having a proximal stereogenic center of the opposite configuration, while the diastereomeric combination of stereogeneities (“mismatch”) is inactive towards any lactide. Polymerization of rac‐LA by the enantiomerically pure catalysts was sluggish and gave stereoirregular poly(lactic acid) (PLA) because selective insertion to a match diastereomer gives a mismatch diastereomer. The racemic catalysts showed higher activity and led to highly heterotactic PLA following polymeryl exchange between two mismatched catalyst enantiomers. A succession of match diastereomers in selective meso‐LA insertions led to syndiotactic PLAs reaching a syndiotacticity degree of α=0.96. This polymer featured a Tm of 153 °C matching the highest reported value, and the highest crystallinity (ΔHm=56 J g−1) ever reported for syndiotactic PLA.
Ligand‐Enabled PdII‐Catalyzed Iterative γ‐C(sp3)−H Arylation of Free Aliphatic Acid
Authors: Dolui Pravas , Das Jayabrata , Chandrashekar Hediyala B. , Anjana S. S. , Maiti Debabrata
Published: July 2019

C−H functionalization of aliphatic carboxylic acids without attaching exogenous auxiliary has been so far limited at the proximal β‐position. In this work, we demonstrate a ligand enabled palladium catalyzed first regioselective distal γ‐C(sp3)−H functionalization of aliphatic carboxylic acids without incorporating an exogenous directing group. Aryl iodides containing versatile functional groups including complex organic molecules are well tolerated with good to excellent yields during the γ‐C(sp3)−H arylation reaction. Interestingly, weak coordination of carboxylate group can be further extended for sequential hetero di‐arylation. Application of the protocol has been showcased by synthesizing substituted α‐tetralone. Mechanistic investigations have been carried out to shed light on the reaction pathway.
Van der Waals Heterostructured MOF‐on‐MOF Thin Films: Cascading Functionality to Realize Advanced Chemiresistive Sensing
Authors: Yao Ming‐Shui , Xiu Jing‐Wei , Huang Qing‐Qing , Li Wen‐Hua , Wu Wei‐Wei , Wu Ai‐Qian , Cao Lin‐An , Deng Wei‐Hua , Wang Guan‐E , Xu Gang
Published: July 2019

Heterostructured metal—organic framework (MOF)‐on‐MOF thin films have the potential to cascade the various properties of different MOF layers in a sequence to produce functions that cannot be achieved by single MOF layers. An integration method that relies on van der Waals interactions, and which overcomes the lattice‐matching limits of reported methods, has been developed. The method deposits molecular sieving Cu‐TCPP (TCPP=5,10,15,20‐tetrakis(4‐carboxyphenyl)porphyrin) layers onto semiconductive Cu‐HHTP (HHTP=2,3,6,7,10,11‐hexahydrotriphenylene) layers to obtain highly oriented MOF‐on‐MOF thin films. For the first time, the properties in different MOF layers were cascaded in sequence to synergistically produce an enhanced device function. Cu‐TCPP‐on‐Cu‐HHTP demonstrated excellent selectivity and the highest response to benzene of the reported recoverable chemiresistive sensing materials that are active at room temperature. This method allows integration of MOFs with cascading properties into advanced functional materials.
Pressure‐Induced Multiphoton Excited Fluorochromic Metal–Organic Frameworks for Improving MPEF Properties
Authors: Chen Cheng‐Xia , Yin Shao‐Yun , Wei Zhang‐Wen , Qiu Qian‐Feng , Zhu Neng‐Xiu , Fan Ya‐Nan , Pan Mei , Su Cheng‐Yong
Published: July 2019

In multiphoton excited fluorescence (MPEF), high‐energy upconversion emission is obtained from low‐energy excitation by absorbance of two or more photons simultaneously. In a pressure‐induced fluorochromic process, the emission energy is switched by outer pressure stimuli. Now, five metal–organic frameworks containing the same ligand with simultaneous multiphoton absorption and pressure‐induced fluorochromic attributes were studied. One‐, two‐, and three‐photon excited fluorescence (1/2/3PEF) can be achieved in the frameworks, which exhibit pressure‐induced blue‐to‐yellow fluorochromism. The performances are closely dependent with the topologies, flexibilities, and packing states of the frameworks and chromophores therein. The multiphoton upconversion performance can be intensified by pressure‐related structural contraction. Over ten‐fold increment in the 2PA active cross‐section up to 2217 GM is achieved in pressed LIFM‐114 compared with the 210 GM for pristine sample at 780 nm.
C3‐Symmetric Assemblies from Trigonal Polycarbene Ligands and MI Ions for the Synthesis of Three‐Dimensional Polyimidazolium Cations
Authors: Zhang Le , Das Rajorshi , Li Chang‐Tao , Wang Yao‐Yu , Hahn F. Ekkehardt , Hua Kai , Sun Li‐Ying , Han Ying‐Feng
Published: July 2019

Metallosupramolecular poly‐NHC‐metal assemblies were prepared from trigonal hexakis (H6‐1 a(PF6)6 and H6‐1 b(PF6)6) or nonakis (H9‐3(BF4)9) imidazolium salts and Ag2O. Complexes [Ag6(1 a)2](PF6)6 and [Ag6(1 b)2](PF6)6 are built from six Ag+ ions sandwiched between two trigonal hexacarbene ligands with an inner and an outer NHC donor in each of the three ligand arms. The metal atoms are arranged in two triangles. The hexakis‐NHC ligands bear cinnamic ester groups at the outlying NHC donors, used in postsynthetic [2+2] cycloaddition reactions linking two hexakis‐NHC ligands by three cyclobutane units to give complexes [Ag6(2 a)](PF6)6 and [Ag6(2 b)](PF6)6 bearing a dodecacarbene ligand. From the related nonakisimidazolium salt H9‐3(BF4)9, complex [Ag9(4)](BF4)9 bearing an octadecacarbene ligand was obtained. Removal of the template metals yielded very large, stable, polyimidazolium cations with 12 or 18 internal imidazolium groups.
Cyclopropanol Warhead in Malleicyprol Confers Virulence of Human‐ and Animal‐Pathogenic Burkholderia Species
Authors: Trottmann Felix , Franke Jakob , Richter Ingrid , Ishida Keishi , Cyrulies Michael , Dahse Hans‐Martin , Regestein Lars , Hertweck Christian
Published: July 2019

Burkholderia species such as B. mallei and B. pseudomallei are bacterial pathogens causing fatal infections in humans and animals (glanders and melioidosis), yet knowledge on their virulence factors is limited. While pathogenic effects have been linked to a highly conserved gene locus (bur/mal) in the B. mallei group, the metabolite associated to the encoded polyketide synthase, burkholderic acid (syn. malleilactone), could not explain the observed phenotypes. By metabolic profiling and molecular network analyses of the model organism B. thailandensis, the primary products of the cryptic pathway were identified as unusual cyclopropanol‐substituted polyketides. First, sulfomalleicyprols were identified as inactive precursors of burkholderic acid. Furthermore, a highly reactive upstream metabolite, malleicyprol, was discovered and obtained in two stabilized forms. Cell‐based assays and a nematode infection model showed that the rare natural product confers cytotoxicity and virulence.
Site‐Selective Functionalization of (sp3)C−H Bonds Catalyzed by Artificial Metalloenzymes Containing an Iridium‐Porphyrin Cofactor
Authors: Gu Yang , Natoli Sean N. , Liu Zhennan , Clark Douglas S. , Hartwig John F.
Published: July 2019

The selective functionalization of one C−H bond over others in nearly identical steric and electronic environments can facilitate the construction of complex molecules. We report site‐selective functionalizations of C−H bonds, differentiated solely by remote substituents, catalyzed by artificial metalloenzymes (ArMs) that are generated from the combination of an evolvable P450 scaffold and an iridium‐porphyrin cofactor. The generated systems catalyze the insertion of carbenes into the C−H bonds of a range of phthalan derivatives containing substituents that render the two methylene positions in each phthalan inequivalent. These reactions occur with site‐selectivity ratios of up to 17.8:1 and, in most cases, with pairs of enzyme mutants that preferentially form each of the two constitutional isomers. This study demonstrates the potential of abiotic reactions catalyzed by metalloenzymes to functionalize C−H bonds with site selectivity that is difficult to achieve with small‐molecule catalysts.
Preparing Perinatal Nurses for Obstetric OR Emergencies by Using Simulations
Authors: Stokes Tanesha L. , Koslan Garrett
Published: July 2019

A cesarean hysterectomy (CH) is an emergency procedure that can save a woman's life in the event of postpartum hemorrhaging. If the CH is anticipated, it can take place in the general OR; however, more complex patients with multiple comorbidities are undergoing cesarean deliveries, resulting in unanticipated CHs and emergent procedures occurring in the obstetric OR. Many perinatal nurses believe they are not properly trained to provide the level of perioperative care required during a CH. Perinatal nurse leaders implemented a perinatal perioperative simulation program to address this knowledge gap. Feedback from perinatal nurses after completing the simulation revealed they gained a comprehensive understanding of the flow of the procedure and the instrumentation needed to perform it. The simulation also improved communication and leadership skills in the obstetric OR. Simulations may help perinatal nurses provide safer, higher quality care when a delivery develops into a high‐risk operative procedure.