bluuebunny/crossref_metadata_2025 huggingface dataset:
Surgical Treatment and Outcomes of Calcaneal Osteomyelitis in Adults: A Systematic Review
Authors: Sabater-Martos Marta , Sigmund Irene Katharina , Loizou Constantinos , McNally Martin
Published: May 2019

Abstract. Introduction: Calcaneal osteomyelitis is an uncommon and challenging condition. In this systematic review we aim to analyse the outcomes from concomitant use of bone debridement and soft tissue management for patients diagnosed with calcaneal osteomyelitis.Materials & Methods: A complete computerised and comprehensive literature search of Pubmed and Cochrane database was undertaken from January 2000 to October 2018. During the review, studies were screened for information about the surgical and antimicrobial treatment, the complications, the reinfection rate and the functional outcome of patients with calcaneal osteomyelitis.Results: Of the 20 eligible studies included, seven (35%) described bone treatment only, six (30%) soft tissue treatment only, five (25%) soft tissue and bone treatment, and two (10%) focused on prognostic factors and differences in outcomes between diabetic and non-diabetic patients.In the studies with bone treatment only, infection recurrence ranged from 0 to 35% and the amputation rate from 0 to 29%. If soft tissue coverage was also needed, both the reinfection rate and amputation rate ranged from 0 to 24%. Studies presenting the functional status generally showed preservation or even improvement of the preoperative ambulatory status.Conclusion: Calcaneal osteomyelitis is difficult to treat. A multidisciplinary approach involving orthopaedic surgeons, plastic surgeons and infectious disease physicians is preferred. The heterogenicity of studies has hindered the development of agreed treatment protocols, which would be useful in clinical practice.
Treatment of a Recurrent Periprosthetic Joint Infection with an Intramedullary Knee Arthrodesis System with Low-Amount Metallic Silver Coating
Authors: Alt Volker , Heiss Christian , Rupp Markus
Published: May 2019

Abstract. We present a case of a recurrent periprosthetic knee infection treated with an intramedullary arthrodesis system coated with low amounts of metallic silver. After a follow-up of 26 months, the patient remained infection free and no silver-related complications were detected. Silver serum concentrations remained below the detection limit of 2 ppb.
La investigación de marketing con dispositivos móviles: un lento despertar
Authors: Pacheco Bernal Carmen
Published: May 2019

De la misma forma que la revolución móvil ha tenido un profundo impacto en la sociedad, ha creado nuevas actividades económicas y ha modificado las existentes, la industria de la investigación de marketing no se ha quedado al margen de todas estas transformaciones. Como se ve en este artículo, las tecnologías móviles han representado nuevos retos y oportunidades para los profesionales del sector, generando nuevas formas de recoger datos de los consumidores que participan en investigaciones de mercado. Sin embargo, y a pesar de las ventajas que supone el uso de metodologías móviles para la industria, su adopción y difusión como técnica de recogida de información sigue siendo bastante limitada. En este artículo se recogen también los datos de uso de metodologías de investigación publicados por el sector y se identifican los principales factores que han influido en la adopción de la investigación de marketing con dispositivos móviles, ya sea incentivando o limitando su utilización.
On the position of subjects in Spanish periphrases: Subjecthood left and right
Authors: Krivochen Diego Gabriel , García Fernández Luis
Published: May 2019

Chains of auxiliary verbs in Spanish allow for the reconceptualization of well-known grammatical problems under the light of understudied structures. In this paper we will deal with issues regarding the position of subjects in declarative and interrogative sentences featuring auxiliary chains. It will become immediately evident that the dichotomy between pre- and post-verbal subjects results inadequate to provide adequate characterisations for the Spanish cases, in contrast to the situation in English. This is so because post-verbal subjects may appear, a priori, to the right of each auxiliary in a chain. These new data, which have received little attention, constitute a challenge for standard hypotheses about the position of subjects in Spanish.
The formal properties of non paradigmatic 'se'
Authors: Romero Juan Romero , Ormazabal Javier
Published: May 2019

Following Oca (1914), this article argues that passive and impersonal se constructions in Spanish are regular transitive constructions where the pronominal clitic seis the argumental subject. Several arguments (secondary predication, non-argumental predicates, control and obviation, anaphora binding, active morphology or its alignment with overt nominative pronouns, among others)show that (i)bothconstructions are active structures, (ii)despite what agreement facts might suggest, in both the internal argument of the verb is not the subject but the direct object throughout the derivation, (iii) se is the active nominative pronominal subject of the construction. We argue that the alleged ‘special’ properties of passive-se are not construction-specific but follow from the lexical specifications of se agreeing with Tense as a quirky subject.
Effectiveness of nasal irrigation devices: a Thai multicentre survey
Authors: Piromchai Patorn , Puvatanond Charoiboon , Kirtsreesakul Virat , Chaiyasate Saisawat , Thanaviratananich Sanguansak
Published: May 2019

Background

Nasal irrigation is widely used as an adjunctive treatment for nasal diseases. There is little evidence regarding the efficacy of the devices used in this procedure. The objective of this survey was to evaluate the effectiveness of nasal irrigation devices based on the experiences of patients and physicians.

Methods

We conducted a multicentre survey study between November 2017 and October 2018. Physician and patient questionnaires were developed based on the available literature and expert opinion. The physician questionnaire was submitted to the Otolaryngology residents and staff of each centre and their network. The physicians were also asked to distribute the patient questionnaire to their patients.

Results

Information regarding 331 devices used by the patients was collected. The mean age of the patients was 45.46 ± 17.19 years (from 5 to 81). Roughly half were male, and half were female (48.6%: 51.4%). Among the high-pressure devices, we found that the high-pressure large-volume nasal irrigation devices yielded significantly higher symptom scores in seven of 12 domains (p < 0.05). Among the large-volume devices, we found that the large-volume high-pressure nasal irrigation devices received significantly higher symptom scores in 4 of 12 domains (p < 0.05). However, a higher proportion of patients using the large-volume high-pressure devices had retained fluid in the sinuses compared to those using large-volume low-pressure devices (p < 0.001).

Conclusions

This survey supports the regular use of nasal irrigation, particularly with large-volume high-pressure devices, as an effective treatment for nasal disease. It may be effective at clearing nasal secretion, improve nasal congestion, decrease post-nasal drip, improve sinus pain or headache, improve taste and smell, and improve sleep quality. It could be used by patients with good compliance and minimal side effects.
Sanitation Status and Waste Disposal Pattern in the Slum Area of Sylhet City Corporation
Authors: Reza Nourin , Alam Rafiul , Ahmed Zia , Begum Sameena , Akhter Syeda Ayshia
Published: May 2019

Aims: Majority of slum people are living in poor quality housing where the absence of basic amenities is a significant issue. The primary aim of the study was to determine the present status of sanitation and waste disposal patterns of the selected slum areas of Sylhet City Corporation (SCC).

Study Design: Both descriptive and analytical methods were applied to reach the final outcome.

Methodology: To conduct the study, 355 samples were collected from five different wards through a constructive questionnaire survey. Key Information Interview (KII), field observation, and focus group discussion (FGD) were also used to collect data.

Results: While the slum people are always struggling to ensure their basic needs, they don’t give emphasis on the sanitary, hygiene, health condition, etc. About 80.4% of slum dwellers defecate in an unhygienic place which may cause various diseases and lead to water pollution by pathogenic microbes. Only 54.9% of people dispose of their waste in a proper way and the others are accountable for environmental pollution by disposing of waste here and there. This study also reveals the socioeconomic condition, health issues, and other water-related challenges of the slum dwellers.

Conclusion: Due to lack of education and knowledge about health and hygiene, unwillingness, poverty, etc. are the possible reasons behind the deterioration of the situation of slum inhabitants. Thus, several remedial measures need to be taken for the improvement of sanitation and waste disposal system.
Hydrological Modeling of the Paligad Watershed (India) Using HSFP Model
Authors: Shah Aamir Ishaq , Sen Sumit , Mishra Anurag
Published: May 2019

For hydrological studies, it is well known that each hydrological system behaves differently and in order to effectively manage those systems, it is necessary to understand their behavior. The hydrological component of Hydrological Simulation Program – FORTRAN (HSPF) model was set up and calibrated for Paligad watershed which is a sub-basin of Aglar watershed in the Uttarakhand state of India. The calibration of the model was done manually and an expert advice system called as HSPEXP+ was used to aid calibration. The values of evaluation indicators such as coefficient of determination (
Seasonal Variations in Imabolo Stream Water Quality in Ankpa Urban Area of Kogi State, Nigeria
Authors: Ocheje Johnmark Friday , Obeta Michael Chukwuma , Jennifer Eze, Eberechukwu , Ogunka Nwankwoala, Hycienth , Elekwachi Wali,
Published: May 2019

Changes in season is one of the important drivers responsible for pollutants transported into surface waters. This study examined the seasonal variations in the quality of Imabolo stream water within Ankpa urban, Kogi State, Nigeria. To achieve the aim of the study, water samples were collected at the peak of the two seasons from seven points along the stream reach corresponding to the different land-use activities in the study area in March and June, 2018. In-situ and laboratory analysis of eighteen physico-chemical and two microbiological parameters were carried out according to standard procedures. Descriptive statistics and t-test were employed to analyze the data obtained for both dry and rainy seasons. The results were compared with WHO and NSDWQ standards for drinking water quality for characterization. The analysis revealed that water samples from six points had elevated values of parameters above the recommended limits for human consumption. The observed seasonal variation indicated that wet season values were higher for all the parameters except DO and Ca2+, while t-test showed significant difference (p < 0.05) in the level of temperature, EC, TDS, turbidity, BOD, COD, nitrate, sulphate, iron, calcium, lead, cadmium, alkalinity, total hardness, total coliforms and E. coli betweendry and rainy season. The study advances innovative recommendations to remediate and improve the quality of the stream water in order to meet the water needs of the users.
Inhibitory Potentials of Trichoderma harzianum and Two Botanicals against Fungi Associated with Postharvest Rots of Ipomoea batatas (L.) Lam
Authors: Sobowale A. A. , Owootomo P. O. , Agbawodike C. R.
Published: May 2019

The mycoparasitic potentials of Trichoderma harzianum, and growth inhibitory effects of Vernonia amygdalina (bitterleaf) and Zingiber officinale (ginger) on rot fungi in Ipomoea batata were examined. Rotting tubers were collected from Agbowo, Ojoo and Bodija markets in Ibadan. They were taken to the laboratory under sterile conditions. Different concentrations of the plants’ extracts and spore suspensions of T. harzianum were prepared. The fungi isolated from the rotting tubers were later cultured on plates impregnated with different concentrations of the extracts and T. harzianum. Incubation was done at 28ºC for 14 days. Data collection was done at 24 hours interval. The fungi isolated were Aspergillus niger and Rhizopus stolonifer. T. harzianum at 1 x 10-3 had a significantly (p≤ 0.05) better pathogens’ inhibition than 1 x 10-5. Inoculation of T. harzianum before the pathogens gave total inhibition. Inhibition of A. niger was significantly (p≤ 0.05) higher than R. stolonifer. Plant extracts from ethanol gave significantly (p≤ 0.05) better pathogens’ inhibitions than that from distilled water. Extracts from both plants gave significantly (p≤ 0.05) better growth inhibition than control. Growth inhibition was significantly (p≤ 0.05) higher at absolute concentration of both extracts than other concentrations. Extract from ginger gave significantly (p≤ 0.05) better inhibition than that from bitter leaf. F-values for model (P> 0.0001) and concentrations (P> 0.0024) for the T. harzianum were highly significant. F-values for model (P> 0.0001), concentration (P>0.0001) and treatment (P>0.0001) for the plants extracts were also highly significant. The results further underscore the mycoparasitic potentials of T. harzianum as well as growth inhibitory effects of Z. officinale and V. amygdalina on fungi rot pathogens of Ipomoea batata.
Maternal Knowledge, Attitudes and Practices towards Prevention and Management of Child Diarrhoea in Urban and Rural Maseru, Lesotho
Authors: Adeleke A. I. , Mhlaba T.
Published: May 2019

Aim: To compare the knowledge, attitudes and practices of mothers in the prevention and management of child diarrhoea, in rural and urban settings of Maseru.

Methodology: This cross-sectional study was carried out in the Domiciliary (Urban) and Tlali (Rural) Health centres in Maseru, within the period of February to May, 2017. Data was collected from 458 mothers/caregivers, with 299 (65%) and 159 (35%) from urban and rural settings respectively. Scores were assigned for the level of knowledge, attitudes, and practices. STATA 14.1 was applied to determine the strengths of associations between categories of the maternal characteristics and the outcome variables.

Results: Aggregation of participants’ knowledge, attitudes, and practices response reveal a statistical significant association with residence. The maternal age range of 30-39 years, P = .03, and mothers with three (3) children, P = .02 were significantly associated with the knowledge of prevention and management of diarrhoea in the rural area. In the urban area, mothers with tertiary education, P = .04, employed, P = .001, unemployed, P = .004, and all categories of monthly income were significantly associated with the knowledge of prevention and management of diarrhoea. For the urban setting, an association between mothers’ attitudes and monthly income between M500 – M1399, P = .05 was observed. The practices of mothers/caregivers in the prevention and management of diarrhoea showed no significant differences in the light of the socio-demographic variables in both settings.

Conclusion: The study revealed low level of maternal knowledge, attitudes and practices in prevention and management of child diarrhea in the rural and urban settings, hence the need to strengthen the existing health education messages on both settings.
General Considerations on Antimicrobial Tests and Conditions Applicable in Textile Industry
Authors: Elshafei Ali Mohamed
Published: May 2019

Due to the globally increasing need for utilizing antimicrobial materials, it is necessary to improve and develop newer methods and techniques for determining the antimicrobial properties of these materials qualitatively and quantitatively, especially in the medical field. Recently there has been a debate among scientists between the difference between antimicrobial test and sterility test. For antimicrobial and microbial resistance, the test is limited to the standard methods to determine the effect of the sample as an antimicrobial without paying attention to the fact that the sample is sterile or not, unless the sample was taken into sterile atmosphere and isolated with a protective suitable sterile package cover after treatment with the antimicrobial agent because the external    atmosphere contains a lot of scattered types of bacterial and fungal microorganisms. In case of sterility test, the sample to be examined should be prepared, isolated and coated from the outside atmosphere, where the presence of microbes on the surface of the sample by standard methods is detected and in some sterilization tests it is prohibited to include an antimicrobial substance to the sample to be tested to avoid the interference with the test. In both cases the tests should be implemented in a sterilized room and conditions according to the recognized scientific principles. In conclusions, the antimicrobial test is used to make sure that the specimen is attained antimicrobial properties or not and the sterilization test is done by ensuring that the sample is free of contaminated microorganisms. This review poses on some factor and conditions affecting antimicrobial action and some standard test methods for determination of antimicrobial and sterility potential of materials.
Asymptomatic Bacteriuria and Candida Colonization among Pregnant Women in a District Hospital in Eastern Uganda
Authors: Fredrick Bakandonda , Shadrack Muwanguzi , Prossy Nakate , Ismail Opolot , Sam Imongit , Mirembe Nnakanwagi Mariam , Julius Nteziyaremye , Nekaka Rebecca , Stanley Iramiot Jacob
Published: May 2019

Background: Urinary tract infection (UTI) is the most common reason for which antimicrobials are prescribed in pregnancy Worldwide. This study aimed to determine the prevalence of asymptomatic bacteriuria, Candida colonization and antimicrobial susceptibility patterns among pregnant women attending antenatal in a District Hospital in Eastern Uganda.

Materials and Methods: A descriptive cross sectional study was conducted in which pregnant mothers who had come for routine antenatal care were counseled and their consents obtained before taking off urine samples for laboratory diagnosis. For those samples found to have pus cells, culture and sensitivity test was done to identify the organisms and determine susceptibility to particular antibiotics and antifungal agents.

Results: Gram negative isolates were more sensitive to meropenem (100%), and ciprofloxacin (93.8%) but less sensitive to trimethoprim/sulphurmethoxazole (20%), Ceftazidime (7%), and Cefepime (6%). Gram positive isolates were more sensitive to vancomycin (100%), meropenem (87%) and linezolid (88.1%) but less sensitive to Cefotaxime (31%) and Trimethoprim / sulphurmethoxazole (14%). All bacteria isolated in this study were multi-drug resistant (MDR). All Candida isolates were susceptible to Econazole and Nystatin whereas all isolates were resistant to Griseofulvin.  

Conclusion: The prevalence of asymptomatic bacteriuria among pregnant women in Butaleja district is high with many of the bacteria isolated exhibiting resistance to the commonly used antibiotics. Antifungal resistance was common in this study.
Outcomes for facilitators of workplace environment improvement applying a participatory approach
Authors: Yoshikawa Etsuko , Kogi Kazutaka
Published: May 2019

Objectives

The purpose of this study was to determine changes in awareness, behavior, and relationships among facilitators who were involved in facilitating the conduct of the participatory workplace improvement program and to examine the facilitators’ outcomes as a result of their active involvement in the program. The outcome components were also examined in relationship to their associations with various factors.

Methods

An anonymous self-administered questionnaire survey was conducted for 83 facilitators. Exploratory factor analysis was applied to determine the facilitators’ outcomes. The relationship between those elements which influenced the outcomes was taken into account by means of hierarchal multiple regression analysis.

Results

The outcomes for facilitators consisted of four sub-concepts: “knowing practical ways and strategies to ensure full participation,” “building confidence and self-development,” “improving safety and health-risk sensitivity,” and “gaining better-than-expected results based on developing relationships with workers.” According to the results of hierarchal multiple regression analysis, facilitators’ outcomes were significantly associated with the realization of creativity, sense of solution for safety and health issues, and facilitators’ involvement.

Conclusions

It is suggested that the role of a facilitator dynamically changes through a participatory workplace improvement program as a key person in the workplace. Supporting acting facilitators’ initiatives in the process of workplace improvement programs, as well as promoting the active involvement of workers and managers were considered useful for effective implementation of workplace improvement programs.
A narrowband active noise control system with reference synthesis
Authors: Lopes Paulo A. C. , Gerald José A. B.
Published: May 2019

Most active noise control (ANC) algorithms require a model of the secondary path (SP). If there are large changes in the SP, online SP modeling algorithms may not be able to follow the changes quickly enough to prevent divergence. In this work, the mirror‐MFxLMS (MMFxLMS) is adapted to narrowband ANC, and the resulting algorithm is analyzed. The MMFxLMS is an algorithm similar to the MFxLMS and FxLMS but has online SP modeling; it is stable for any SP estimate and does not require auxiliary noise. In addition, a technique to alternate between MFxLMS and MMFxLMS is proposed, resulting in the M3FxLMS algorithm, which does not sacrifice performance and assures stability. However, the M3FxLMS requires a reference signal that is not available in feedback ANC. Feedback ANC is important in many practical cases, for instance, in ANC headphones. To solve this problem, a technique is proposed to synthesize a reference formed by a sum of sinusoids using measurements from the error sensor signal. This technique uses the fast Fourier transform to obtain estimates of the harmonic frequencies of the periodic noise components, and then refines and tracks these using a phase‐locked loop (PLL). The resulting algorithm enables a stable ANC system, even under large and sudden changes in the SP. The proposed PLL is also new and has a lock‐in range equal to the full band of the system.
Ultralight and Flexible Monolithic Polymer Aerogel with Extraordinary Thermal Insulation by A Facile Ambient Process
Authors: Li Man , Qin Zihao , Cui Ying , Yang Chiyu , Deng Changyu , Wang Yunbo , Kang Joon Sang , Xia Hongyan , Hu Yongjie
Published: May 2019

High performance thermal insulation materials are desired for a wide range of applications in space, buildings, energy, and environments. Here, a facile ambient processing approach is reported to synthesize a highly insulating and flexible monolithic poly(vinyl chloride) aerogel. The thermal conductivity is measured respectively as 28 mW (m K)−1 at atmosphere approaching the air conductivity and 7.7 mW (m K)−1 under mild evacuation condition. Thermal modeling is performed to understand the thermal conductivity contributions from different heat transport pathways in air and solid. The analysis based on the Knudsen effect and scattering mean free paths shows that the thermal insulation performance can be further improved through the optimization of porous structures to confine the movement of air molecules. Additionally, the prepared aerogels show superhydrophobicity due to the highly porous structures, which enables new opportunities for surface engineering. Together, the study demonstrates an energy‐saving and scalable ambient‐processing pathway to achieve ultralight, flexible, and superhydrophobic poly(vinyl chloride) aerogel for thermal insulation applications.
Cooperative Behaviors in Amplified Emission from Single Microcrystals of Thiophene/Phenylene Co‐Oligomers toward Organic Polariton Laser
Authors: Yanagi Hisao , Sasaki Fumio , Yamashita Kenichi
Published: May 2019

After successful commercialization of organic light‐emitting diodes (OLEDs), organic semiconductor lasers have become a practical research target for versatile optoelectronic applications. Realization of electrically pumped lasing with molecular materials faces critical issues such as exciton quenching by injected carriers, nonradiative triplet states, and difficulties in introduction of resonators. One of potential routes to overcome them is to utilize polaritonic emission based on cooperative coupling of photons with excitons and/or phonons in molecular crystals. This report overviews cooperative behaviors observed in amplified emissions from single‐crystal thiophene/phenylene co‐oligomers (TPCOs) and discusses their expected potential toward organic polariton lasers. First, amplified emission accompanied with unusual time delay, spectral splitting, and fluence dependence of lasing threshold is presented, suggesting superfluorescence from macroscopically correlated molecular excitons, not based on the conventional stimulated emission process. Second, selectively enhanced Raman scattering under off‐resonant condition is shown, which is interpreted as a result of contribution of coherent vibrations in the TPCO crystals. Then, angle‐resolved spectroscopies demonstrate a stable existence of exciton polaritons at room temperature in microcavity devices with TPCO crystals. It is concluded that all those unique behaviors are ascribed to the TPCO excitons and vibrations having large oscillator strength under the uniaxially oriented molecular alignment.
Light‐Controlled Micromotors and Soft Microrobots
Authors: Palagi Stefano , Singh Dhruv P. , Fischer Peer
Published: May 2019

Mobile microscale devices and microrobots can be powered by catalytic reactions (chemical micromotors) or by external fields. This report is focused on the role of light as a versatile means for wirelessly powering and controlling such microdevices. Recent advances in the development of autonomous micromotors are discussed, where light permits their actuation with unprecedented control and thereby enables advances in the field of active matter. In addition, structuring the light field is a new means to drive soft microrobots that are based on (photo‐) responsive polymers. The behavior of the two main classes of thermo‐ and photoresponsive polymers adopted in microrobotics (poly(N‐isopropylacrylamide) and liquid‐crystal elastomers) is analyzed, and recent applications are reported. The advantages and limitations of controlling micromotors and microrobots by light are reviewed, and some of the remaining challenges in the development of novel photo‐active materials for micromotors and microrobots are discussed.
Light‐Activated Liquid Crystalline Hierarchical Architecture Toward Photonics
Authors: Ma Ling‐Ling , Hu Wei , Zheng Zhi‐Gang , Wu Sai‐Bo , Chen Peng , Li Quan , Lu Yan‐Qing
Published: May 2019

Hierarchical architectures are of vital importance in materials science and nanotechnology. Among various building blocks, liquid crystals (LCs) have attracted particular attention due to their excellent controllability of self‐assembly behavior and the resultant physical properties. In recent years, interest in light‐activated LC hierarchical superstructures has emerged for a wide range of applications beyond LC displays. This report consists of two main parts: the light‐activated LC hierarchical architectures and their corresponding photonic applications. In the first part, different smectic layer curvature controlling methods are introduced to produce periodic defect arrays. By taking the advantages of photoalignment techniques and light‐driven molecular motors, cholesteric LC helical superstructures are highly manipulated, including pitch tuning, helix rotation, and chirality inversion. As a mutually concerned scientific issue, the photoresponsive properties of blue phase (BP) hierarchical superstructures are also introduced, enabling unique BP materials and devices driven by a facile light stimulation. Moreover, traditional optics (microlens and beam steering) and advanced photonics (specific optical field generation and LC lasers) are reviewed in the second part. It is believed that the developments introduced here can open a door for the concept of “smart optical materials” based on the self‐assembled soft LC superstructures.
Halogen‐Containing TPA‐Based Luminogens: Different Molecular Packing and Different Mechanoluminescence
Authors: Yu Yun , Wang Can , Wei Yao , Fan Yuanyuan , Yang Jie , Wang Jiaqiang , Han Mengmeng , Li Qianqian , Li Zhen
Published: May 2019

Organic mechanoluminescence (ML) materials have attracted much attention for their various application prospects in luminescent devices. However, the pace of their development has been greatly limited by the unclear inherent mechanism. Herein, halogen atoms are systematically introduced into ML for the first time to deeply explore the light‐emitting process and internal mechanism. Thus, a series of triphenylamine (TPA) derivatives is obtained with diverse ML properties, including TPA‐oF, TPA‐mF, TPA‐pF, TPA‐oCl, TPA‐mCl, TPA‐pCl, TPA‐oBr, TPA‐mBr, TPA‐pBr, and TPA‐ph. Among them, with the introduced chlorine and bromine atoms in the para‐position of the phenyl ring in TPA‐ph, the resultant TPA‐pCl and TPA‐pBr demonstrate bright ML; whereas the introduced fluorine atom in TPA‐pF drastically reduces the ML performance. Careful analysis of their optical properties and crystal structures coupled with theoretical calculations confirms that different halogen atoms in the TPA derivatives can really lead to diverse intermolecular interactions, and the strong intermolecular interactions are actually beneficial for the ML effect by reducing energy loss through nonradiative relaxation channels under a stimulus of mechanical force; however, unsatisfying ML performance is observed in the crystal with an overtight molecular packing, on account of the unbreakable crystals with high rigidity.
Intermixed Cation–Anion Aqueous Battery Based on an Extremely Fast and Long‐Cycling Di‐Block Bipyridinium–Naphthalene Diimide Oligomer
Authors: Perticarari Sofia , Doizy Tom , Soudan Patrick , Ewels Chris , Latouche Camille , Guyomard Dominique , Odobel Fabrice , Poizot Philippe , Gaubicher Joel
Published: May 2019

Aqueous batteries, particularly those integrating organic active materials functioning in a neutral pH environment, stand out as highly promising contenders in the stationary electrochemical storage domain, owing to their unparalleled safety, sustainability, and low‐cost materials. Herein, a novel di‐block oligomer, serving as the negative electrode of an all‐organic aqueous battery, is shown to offer exceptional output capabilities. The battery's performance is further enhanced by a unique intermixed p/n‐type storage mechanism, which is able to simultaneously exchange light and naturally abundant Na+, Mg2+, and Cl−. Reaching up to 105 mAh g−1, this system shows remarkable capacity retention for several thousand cycles (6500 cycles, ≈40 days) in various neutral electrolytes, including raw ocean water (≈3000 cycles, ≈75 days). The surprisingly fast kinetics of this di‐block oligomer allow to attain an unmatched specific capacity of near to 60 mAh g−1electrode while entirely devoid of conducting additives, and more than 80 mAh g−1electrode with 10% carbon additive, as well as displaying an areal capacity as high as 3.4 mAh cm−2 at C rate. Full cell validation was demonstrated over 1600 cycles by virtue of a commercial 2,2,6,6‐tétraméthylpipéridin‐1‐yl)oxyl (TEMPO) molecule, which permitted an energy density of close to 40 Wh kg−1materials at C rate in a self‐pH‐buffered and inexpensive aqueous electrolyte.
Thin Film Encapsulation of Organic Solar Cells by Direct Deposition of Polysilazanes from Solution
Authors: Channa Iftikhar Ahmed , Distler Andreas , Zaiser Michael , Brabec Christoph J. , Egelhaaf Hans‐Joachim
Published: May 2019

Organic electronic devices (OEDs), e.g., organic solar cells, degrade quickly in the presence of ambient gases, such as water vapor and oxygen. Thus, in order to extend the lifetime of flexible OEDs, they have to be protected by encapsulation. A solution‐based encapsulation method is developed, which allows the direct deposition of the diffusion barrier on top of OEDs, thus avoiding lamination of barrier films. The method is based on the deposition of a perhydropolysilazane (PHPS) ink and its subsequent conversion into a silica layer by deep UV irradiation. The resulting barrier films show water vapor transmission rates (WVTRs) of <10−2 g m−2 d−1 (40 °C/85% relative humidity (RH)) and oxygen transmission rates (OTRs) of <10−2 cm3 m−2 d−1 bar−1 at ambient conditions. Flexibility of the resulting barrier films is improved by coating a barrier stack of several thin PHPS layers alternating with organic polymer interlayers. These stacks show an increase of WVTR values by less than 10% after 3000 bending cycles. Direct coating of the PHPS films on top of organic solar cells enhances the device lifetime in damp heat conditions from a few hours to beyond 300 h.
Oblate Spheroidal Triboelectric Nanogenerator for All‐Weather Blue Energy Harvesting
Authors: Liu Guanlin , Guo Hengyu , Xu Sixing , Hu Chenguo , Wang Zhong Lin
Published: May 2019

Triboelectric nanogenerators (TENGs) provide one of the most promising techniques for large‐scale blue energy harvesting. However, lack of reasonable designs has largely hindered TENG from harvesting energy from both rough and tranquil seas. In this paper, an oblate spheroidal TENG assembled by two novel TENG parts is elaborately designed for both situations. The TENG in the upper part is based on spring steel plates without other substrate materials, which makes it possible to output considerable power in rough seas and occupy small space. The TENG in the lower part consists of two copper‐coated polymer films and a rolling ball which can capture small wave energy from tranquil seas. The working mechanism and output performance are systematically studied. A maximum open‐circuit voltage of 281 V and a short‐circuit current of 76 µA can be achieved by one upper part, enough to charge a commercial capacitor for potential applications. More important, the proposed oblate spheroidal shell not only guarantees high sensitivity of the TENG in the lower part, but also qualifies the TENG with unique self‐stabilization and low consumables for the next generation of TENGs with new structural design toward all‐weather blue energy harvesting.
Novel Graphene Hydrogel/B‐Doped Graphene Quantum Dots Composites as Trifunctional Electrocatalysts for Zn−Air Batteries and Overall Water Splitting
Authors: Tam Tran Van , Kang Sung Gu , Kim Mun Ho , Lee Seung Geol , Hur Seung Hyun , Chung Jin Suk , Choi Won Mook
Published: May 2019

Herein, a facile, one‐step hydrothermal route to synthesize novel all‐carbon‐based composites composed of B‐doped graphene quantum dots anchored on a graphene hydrogel (GH‐BGQD) is demonstrated. The obtained GH‐BGQD material has a unique 3D architecture with high porosity and large specific surface area, exhibiting abundant catalytic active sites of B‐GQDs as well as enhanced electrolyte mass transport and ion diffusion. Therefore, the prepared GH‐BGQD composites exhibit a superior trifunctional electrocatalytic activity toward the oxygen reduction reaction, oxygen evolution reaction, and hydrogen evolution reaction with excellent long‐term stability and durability comparable to those of commercial Pt/C and Ir/C catalysts. A flexible solid‐state Zn–air battery using a GH‐BGQD air electrode achieves an open‐circuit voltage of 1.40 V, a stable discharge voltage of 1.23 V for 100 h, a specific capacity of 687 mAh g−1, and a peak power density of 112 mW cm−2. Also, a water electrolysis cell using GH‐BGQD electrodes delivers a current density of 10 mA cm−2 at cell voltage of 1.61 V, with remarkable stability during 70 h of operation. Finally, the trifunctional GH‐BGQD catalyst is employed for water electrolysis cell powered by the prepared Zn–air batteries, providing a new strategy for the carbon‐based multifunctional electrocatalysts for electrochemical energy devices.
Selective Aerobic Oxygenation of Tertiary Allylic Alcohols with Molecular Oxygen
Authors: Zhu Bencong , Shen Tao , Huang Xiaoqiang , Zhu Yuchao , Song Song , Jiao Ning
Published: May 2019

Aerobic epoxidation of tertiary allylic alcohols remains a significant challenge. Reported here is an efficient and highly chemoselective copper‐catalyzed epoxidation and semipinacol rearrangement reaction of tertiary allylic alcohols with molecular oxygen. The solvent 1,4‐dioxane activates dioxygen, thereby precluding the addition of a sacrificial reductant.
Breslow Intermediates from a Thiazolin‐2‐ylidene and Fluorinated Aldehydes: XRD and Solution‐Phase NMR Spectroscopic Characterization
Authors: Paul Mathias , Neudörfl Jörg‐M. , Berkessel Albrecht
Published: May 2019

The first generation and X‐ray diffraction (XRD) analysis of a crystalline Breslow intermediate (BI) derived from a thiazolin‐2‐ylidene, that is, the aromatic heterocycle present in vitamin B1, is reported. Key to success was the combined use of pentafluorobenzaldehyde and a thiazolin‐2‐ylidene carrying an enol‐stabilizing dispersion energy donor as N‐substituent. A so‐called primary intermediate (PI) could be isolated in protonated form (pPI) as well and analyzed by XRD. Furthermore, the first stable BI derived from an aromatic thiazolin‐2‐ylidene and an aliphatic aldehyde (trifluoroacetaldehyde) was prepared and characterized by NMR spectroscopy in solution. When switching to a saturated thiazolidin‐2‐ylidene, reaction with pentafluorobenzaldehyde afforded a new BI in solution (NMR spectroscopy). Attempts to crystallize the latter BI resulted in the isolation of a novel thiazolidin‐2‐ylidene dimer that had undergone rearrangement to a hexahydro[1,4]‐thiazino[3,2‐b]‐1,4‐thiazine.
The Interplay between Structure and Product Selectivity of CO2 Hydrogenation
Authors: Yang Chengsheng , Liu Sihang , Wang Yanan , Song Jimin , Wang Guishuo , Wang Shuai , Zhao Zhi‐Jian , Mu Rentao , Gong Jinlong
Published: May 2019

Identification of the active structure under reaction conditions is of great importance for the rational design of heterogeneous catalysts. However, this is often hampered by their structural complexity. The interplay between the surface structure of Co3O4 and the CO2 hydrogenation is described. Co3O4 with morphology‐dependent crystallographic surfaces presents different reducibility and formation energy of oxygen vacancies, thus resulting in distinct steady‐state composition and product selectivity. Co3O4‐0 h rhombic dodecahedra were completely reduced to Co0 and CoO, which presents circa 85 % CH4 selectivity. In contrast, Co3O4‐2 h nanorods were partially reduced to CoO, which exhibits a circa 95 % CO selectivity. The crucial role of the Co3O4 structure in determining the catalytic performance for higher alcohol synthesis over CuCo‐based catalysts is demonstrated. As expected, Cu/Co3O4‐2 h shows nine‐fold higher ethanol yield than Cu/Co3O4‐0 h owing to the inhibition for methanation.
Investigation of an Unusual Crystal Habit of Hydrochlorothiazide Reveals Large Polar Enantiopure Domains and a Possible Crystal Nucleation Mechanism
Authors: Thomas Sajesh P. , Grosjean Arnaud , Flematti Gavin R. , Karton Amir , Sobolev Alexandre N. , Edwards Alison J. , Piltz Ross O. , Iversen Bo B. , Koutsantonis George A. , Spackman Mark A.
Published: May 2019

The observation of an unusual crystal habit in the common diuretic drug hydrochlorothiazide (HCT), and identification of its subtle conformational chirality, has stimulated a detailed investigation of its crystalline forms. Enantiomeric conformers of HCT resolve into an unusual structure of conjoined enantiomorphic twin crystals comprising enantiopure domains of opposite chirality. The purity of the domains and the chiral molecular conformation are confirmed by spatially revolved synchrotron micro‐XRD experiments and neutron diffraction, respectively. Macroscopic inversion twin symmetry observed between the crystal wings suggests a pseudoracemic structure that is not a solid solution or a layered crystal structure, but an unusual structural variant of conglomerates and racemic twins. Computed interaction energies for molecular pairs in the racemic and enantiopure polymorphs of HCT, and the observation of large opposing unit‐cell dipole moments for the enantiopure domains in these twin crystals, suggest a plausible crystal nucleation mechanism for this unusual crystal habit.
Duplex‐gesteuerte Umfaltung in neuartige G‐Quadruplex‐(3+1)‐ Hybridkonformationen
Authors: Karg Beatrice , Mohr Swantje , Weisz Klaus
Published: May 2019

Es konnte gezeigt werden, dass sich ein DNA‐Oligonukleotid der Sequenz d(GCGTG3TCAG3TG3TG3ACGC) mit kurzen, komplementären Überhangsequenzen am 5′‐ und 3′‐Ende in drei unterschiedliche Quadruplexspezies faltet. Dagegen bildet das entsprechende Oligomer ohne Basenkomplementarität der beiden Überhangsequenzen nur eine einzige parallele G‐Quadruplexstruktur. Über einen Vergleich von NMR‐Spektren der polymorphen Probe mit genau definierten G‐Quadruplexen, die über einen gezielten Einbau von syn‐präferierenden 8‐Bromguanosin‐Analoga erhalten wurden, konnten die drei koexistierenden Quadruplexstrukturen eindeutig zugeordnet und strukturell charakterisiert werden. Dabei liegen neben der parallelen Form zwei weitere (3+1)‐Hybridstrukturen vor. Diese weisen mit einem Lateralloop, gefolgt von zwei Propellerloops, eine bisher experimentell noch nicht eindeutig nachgewiesene Looparchitektur auf. Beide Hybridquadruplexe haben die gleiche Topologie und unterscheiden sich nur in den anti→syn‐Abfolgen entlang der G‐Trakte sowie den Stapelwechselwirkungen zwischen den G‐Tetraden.
Deracemisierung von α‐verzweigten Carbonsäuren durch katalytische asymmetrische Protonierung von Bis‐Silylketenacetalen mit Wasser oder Methanol
Authors: Mandrelli Francesca , Blond Aurélie , James Thomas , Kim Hyejin , List Benjamin
Published: May 2019

Wir beschreiben eine hochenantioselektive katalytische Protonierung von Bis‐Silylketenacetalen. Unsere Methode liefert α‐verzweigte Carbonsäuren, einschließlich nichtsteroidaler entzündungshemmender Arylpropionsäuren wie Ibuprofen, in hoher Enantiomerenreinheit und Ausbeute. Der Prozess kann in eine generelle Deracemisierung von α‐verzweigten Carbonsäuren integriert werden, die eine doppelte Deprotonierung und Silylierung gefolgt von der katalytisch asymmetrischen Protonierung umfasst.
Structure of the Au23−xAgx(S‐Adm)15 Nanocluster and Its Application for Photocatalytic Degradation of Organic Pollutants
Authors: Liu Chao , Ren Xiuqing , Lin Feng , Fu Xuemei , Lin Xinzhang , Li Tao , Sun Keju , Huang Jiahui
Published: May 2019

Ligands play an important role in determining the atomic arrangement within the metal nanoclusters. Here, we report a new nanocluster [Au23−xAgx(S‐Adm)15] protected by bulky adamantanethiol ligands which was obtained through a one‐pot synthesis. The total structure of [Au23−xAgx(S‐Adm)15] comprises an Au13−xAgx icosahedral core, three Au3(SR)4 units, and one AgS3 staple motif in contrast to the 15‐atom bipyramidal core previously seen in [Au23−xAgx(SR)16]. UV/Vis spectroscopy indicates that the HOMO–LUMO gap of [Au23−xAgx(S‐Adm)15] is 1.5 eV. DFT calculations reveal that [Au19Ag4(S‐Adm)15] is the most stable structure among all structural possibilities. Benefitting from Ag doping, [Au23−xAgx(S‐Adm)15] exhibits drastically improved photocatalytic activity for the degradation of rhodamine B (RhB) and phenol under visible‐light irradiation compared to Au23 nanoclusters.
Duplex‐Guided Refolding into Novel G‐Quadruplex (3+1) Hybrid Conformations
Authors: Karg Beatrice , Mohr Swantje , Weisz Klaus
Published: May 2019

The oligomer d(GCGTG3TCAG3TG3TG3ACGC) with short complementary flanking sequences at the 5′‐ and 3′‐ends was shown to fold into three different DNA G‐quadruplex species. In contrast, a corresponding oligomer that lacks base complementarity between the two overhang sequences folds into a single parallel G‐quadruplex. The three coexisting quadruplex structures were unambiguously identified and structurally characterized through detailed spectral comparisons with well‐defined G‐quadruplexes formed upon the deliberate incorporation of syn‐favoring 8‐bromoguanosine analogues into specific positions of the G‐core. Two (3+1) hybrid structures coexist with the parallel fold and feature a novel lateral–propeller–propeller loop architecture that has not yet been confirmed experimentally. Both hybrid quadruplexes adopt the same topology and only differ in their pattern of anti→syn transitions and tetrad stackings.
Green synthesis and characterizations of Nickel oxide nanoparticles using leaf extract of Rhamnus virgata and their potential biological applications
Authors: Iqbal Javed , Abbasi Banzeer Ahsan , Mahmood Tariq , Hameed Safia , Munir Akhtar , Kanwal Sobia
Published: May 2019

In the present report, Nickel oxide nanoparticles (NiONPs) were synthesized using Rhamnus virgata (Roxb.) (Family: Rhamnaceae) as a potential stabilizing, reducing and chelating agent. The formation, morphology, structure and other physicochemical properties of resulting NiONPs were characterized by Ultra violet spectroscopy, X‐ray diffraction (XRD), Fourier Transform Infrared analysis (FTIR), Scanning electron microscopy (SEM), Energy‐dispersive‐spectroscopy (EDS), Transmission electron microscopy (TEM), Raman spectroscopy and dynamic light scattering (DLS). Detailed in vitro biological activities revealed significant therapeutic potential for NiONPs. The antimicrobial efficacy of biogenic NiONPs was demonstrated against five different gram positive and gram negative bacterial strains. Klebsiella pneumoniae and Pseudomonas aeruginosa (MIC: 125 μg/mL) were found to be the least susceptible and Bacillus subtilis (MIC: 31.25 μg/mL) was found to be the most susceptible strain to NiONPs. Biogenic NiONPs were reported to be highly potent against HepG2 cells (IC50: 29.68 μg/ml). Moderate antileishmanial activity against Leishmania tropica (KMH23) promastigotes (IC50: 10.62 μg/ml) and amastigotes (IC50: 27.58 μg/ml) cultures are reported. The cytotoxic activity was studied using brine shrimps and their IC50 value was recorded as 43.73 μg/ml. For toxicological assessment, NiONPs were found compatible towards human RBCs (IC50: > 200 μg/ml) and macrophages (IC50: > 200 μg/ml), deeming particles safe for various applications in nanomedicines. Moderate antioxidant activities: total antioxidant capacity (TAC) (51.43%), 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) activity (70.36%) and total reducing power (TRP) (45%) are reported for NiONPs. In addition, protein kinase and alpha amylase inhibition assays were also performed. Our results concluded that Rhamnus virgata synthesized NiONPs could find important biomedical applications with low cytotoxicity to normal cells.