bluuebunny/crossref_metadata_2025 huggingface dataset:
Leaving Groups in Metal‐Free Arylations: Make Your Choice!
Authors: Raviola Carlotta , Protti Stefano
Published: May 2020

Cleavage of an Aryl–Leaving Group bond (Ar–LG) is the key step in most arylation processes for the synthesis of highly functionalized (hetero)arenes. In metal‐free arylations, depending on the nature of the starting substrates, different thermal and photochemical approaches can be adopted: Single Electron Transfer (SET) and homolysis/heterolysis of an Ar–LG bond to afford an aryl radical (Ar·) or an aryl cation (Ar+), respectively. Accordingly, the nature of LG plays a key‐role in determining the mechanism and efficiency of the process.
Photophysical Properties of Silyl‐Substituted Stilbene Derivatives
Authors: Maeda Hajime , Horikoshi Ryo , Yamaji Minoru , Furuyama Taniyuki , Segi Masahito
Published: May 2020

The effects of silyl groups on the structural, absorption, fluorescence, and photoisomerization properties of stilbenes were investigated. In comparison to that of the parent stilbene (1), fluorescence quantum yields (Φf) of Me3Si‐substituted stilbenes 2–4 and 6 in solution were higher. Derivative 5, in which Me3Si groups are present at all ortho positions of the arene moieties, did not fluoresce at room temperature. The absorption and fluorescence wavelength maxima of Me3SiMe2Si‐substituted stilbene 7 occurred at longer wavelengths compared to those of the Me3Si analog 2. The results of theoretical calculations showed that this difference is a consequence of an increase in the HOMO energy of 7 caused by orbital interaction between π‐system and the σ(Si–Si) orbital. Stilbene 14, with two Me3Si‐C≡C groups at both para positions, had a high Φf (0.95). The calculated transition dipole moment (µ) was well correlated with Φf. Derivative 21, which contains Ph2N and Me3SiC≡C groups exhibited solvatofluorochromism because it possesses a twisted intramolecular charge transfer (TICT) excited state in which the Ph2N group and the aromatic ring are orthogonal.
Regioselective Deuteration of a 3,4‐Dialkoxypyrroline N‐Oxide and Synthesis of 8a‐d‐Indolizidines
Authors: Ranzenigo Anna , Mercurio Chiara , Karrenbrock Maurice , Cordero Franca M. , Cardini Gianni , Pagliai Marco , Brandi Alberto
Published: May 2020

A simple and efficient method for C‐2 deuterium labeling of 3,4‐di‐tert‐butoxypyrroline N‐oxide, a useful chiral building block in azaheterocycles syntheses, is presented. Selective and quantitative deuterium incorporation (> 99 %) was achieved by base‐catalyzed H/D exchange in D2O under mild reaction conditions. A mechanistic pathway based on kinetic and computational data was proposed. The labeled nitrone was used in the synthesis of C‐8a deuterated (1R,2R,8aR)‐lentiginosine.
A One‐Pot Copper‐Catalyzed 3‐Fold C–N Bond Coupling Strategy to the Synthesis of Substituted Benzimidazoles
Authors: Subramanian Parthasarathi , Kaliappan Krishna P.
Published: May 2020

An efficient, one‐pot copper catalyzed 3‐fold C–N bond‐coupling strategy leading to pharmaceutically relevant benzimidazole heterocycles is reported. Our strategy involves a copper catalyzed intramolecular C–N coupling of N,N'‐bis(2‐bromophenyl)formamidine to provide 1‐(2‐bromophenyl)‐1H‐benzimidazole which upon intermolecular coupling with 2‐amino pyridines and a cascade sp2 C–H amination furnished a range of benzimidazo[1,2‐a]benzimidazoles.
Evaluation of xanthine oxidase inhibitory activity of flavonoids by an online capillary electrophoresis‐based immobilized enzyme microreactor
Authors: Wu Zhao‐Yu , Zhang Hao , Li Feng , Yang Feng‐Qing
Published: May 2020

Xanthine oxidase (XOD) is a key enzyme in the human body to produce uric acid, and its inhibitor can be used for the treatment of hyperuricemia and gout. In this study, an online CE‐based XOD immobilized enzyme microreactor (IMER) was developed for the enzyme kinetics assays and inhibitor screening. After 30 consecutive runs, the XOD activity remained about 95.6% of the initial immobilized activity. The Michaelis–Menten constant (Km) of the immobilized XOD was determined as 0.39 mM using xanthine as substrate. The half‐maximal inhibitory concentration and inhibition constant of the known inhibitor 4‐aminopyrazolo[3,4‐d]pyrimidine on XOD were determined as 11.9 and 5.2 μM, respectively. Then, the developed method was applied to evaluate the XOD inhibitory activity of 10 flavonoids, which indicated that dihydroquercetin, quercetin, biochanin A, and epicatechin had significant inhibitory effect on XOD. In addition, molecular docking results verified that the binding energy of the flavonoids with enzyme were in line with their inhibitory activity determined by XOD–IMER. Therefore, the developed XOD–IMER is a potential tool for the primary screening of XOD inhibitors from natural products.
Numerical study of cuttings transport of nanoparticle‐based drilling fluid
Authors: Al‐Yasiri Mortatha , Al‐Gailani Amthal , Wen Dongsheng
Published: May 2020

Cuttings transportation from the drill bit, through the annulus, to the surface is one of the most important functions performed by drilling fluid. The prediction of drilling fluid's performance to transport cuttings in the annulus is very complex task due to the presence of numerous parameters. Nanoparticles (NPs) have been recently introduced into drilling fluid to engineer its properties and enhance its performance. Nevertheless, the lifting capacity has not been sufficiently investigated. The understanding of the influence and the mechanisms responsible for the improvement in cuttings transport process can further advance the application of NPs for drilling fluids. Computational fluid dynamics (CFD) is widely used as a numerical technique in handling complex multiphase flow problems in different operational conditions. The present work has taken the advantages of CFD to computationally analyze the influence of NPs and the effects of various parameters such as drilling fluids rheology, flow rate, pipe rotation, cuttings density, shape, concentration, and drilling fluids‐cuttings particle coupling regimes on the cuttings transport in a vertical wellbore. The CFD simulation is carried out by using transient solver of ANSYS‐FLUENT commercial code. The dense discrete phase model is used to overcome the main shortcomings of previous Eulerian based approaches. Good agreement has been achieved between the simulation and the published experimental results. It showed that the fluid viscosity and cuttings transport process can be significantly enhanced by adding nanomaterials to the fluid, and the process is highly influenced by cuttings characteristics such as in situ concentration, shape, and density.
Practice on treating pharmaceutical compounds (antibiotics) present in wastewater using biosorption techniques with different biowaste compounds. A review
Authors: Magesh N. , Annam Renita A. , Senthil Kumar P.
Published: May 2020

Pharmaceutical and Public Care Products (PPCP) enable a healthy lifestyle for individuals, but the non‐metabolized components get released to the environment, which creates an adverse impact on the environment, especially the aquatic ecosystem. PPCP is considered a secondary pollutant, but it has the potential to become a primary pollutant due to its bioaccumulation and lasting detrimental effects. Primary wastewater treatments like coagulation, sedimentation, and flocculation are not suitable for the exclusion of these contaminants due to their low density and ability to form an emulsion with other constituents. Adsorption is a promising technique due to ease of application, low‐cost, and comparatively good efficiency. Adsorbents made from the biological waste make process economical, and proper selection of adsorbent material for the removal of PPCP components reduces the discharge of solid waste to the environment. This review briefly analysis and explain the adsorbents used for seven commonly used second‐generation antibiotics, which are used for tract infection.
An alternative approach to reclaim spent nickel–metal hydride batteries
Authors: Kuo Yi‐Ming , Huang Kuo‐Lin , Wang Jian‐Wen , Tsai Cheng‐Hsien , Lin Sheng‐Lun
Published: May 2020

Spent nickel‐metal hydride (NiMH) batteries contained some valuable metals which are worthy of recovery. This study focuses on the reclamation of spent NiMH batteries using an alternative approach, thermal separation process (TSP). Spent NiMH batteries were mixed with cullet, limestone, and dolomite. The mixture was heated to 1,450°C and cooled to room temperature without forced convection. During the TSP, the output‐materials were divided into slag, ingot, and flue gas according to the boiling points and densities of metals. Results show that metals having a relatively low boiling points, such as Cd, Hg, Pb, and Zn, were mostly vaporized into flue gas. Among the metals retained in molten materials, Co, Cu, Fe, and Ni predominately went into the bottom layer and formed the ingot; on the contrary, Al, Ca, Mg, and Si stayed in the upper layer and formed slag. Therefore, the main components of slag were Si (316,000 mg/kg), Ca (289,000 mg/kg), and Mg (32,400 mg/kg) and the major crystalline phases were CaSiO3, CaMgSi2O6, and Ca2MgSi2O7. The slag was pended as non‐hazardous materials and could be reused as road pavement or building materials. The ingot had high levels of Ni (408,000 mg/kg), Fe (349,000 mg/kg), and Co (55,400 mg/kg) and could act as an additive in stainless steel manufacturing process.
Effect of hairy surface on heat production and thermal insulation on the building
Authors: Sogukpinar Haci
Published: May 2020

In the extreme wind and cold weather conditions, animals have developed incredible protection techniques in order to achieve the regulation of body thermal insulation. While birds fluff their feathers to reduce heat loss, some animals take advantage of the other varying unique structures of the skin. In this study, inspired by birds, the effect of hairy surfaces like hedgehog skin on thermal insulation and also heat production at the low‐speed wind on the building wall surface was investigated numerically by using the finite element method. For this, a portion of the wall surface was covered with rigid barbs to increase friction on the wall, and for the comparison, a part of the surface was left smooth without any coating. Menter's shear stress transport (SST) turbulence model by algebraic multigrid solver was used for the modeling of wind motion and heat transfer equations by direct solver PARDISO was used to simulate heat transfer in the solid and fluid environment. According to the numerical calculation, the wind speed slows down along the rough surface, high‐pressure zone on the surface (a thick no‐slip boundary region) was created and a part of wind energy was converted to extra heat and especially the convective heat loss due to the movement of the wind on the surface was reduced, and finally, the building was insulated further by creating a stagnant air layer in the barbs.
An internet of health things‐driven deep learning framework for detection and classification of skin cancer using transfer learning
Authors: Khamparia Aditya , Singh Prakash Kumar , Rani Poonam , Samanta Debabrata , Khanna Ashish , Bhushan Bharat
Published: May 2020

As specified by World Health Organization, the occurrence of skin cancer has been growing over the past decades. At present, 2 to 3 million nonmelanoma skin cancers and 132 000 melanoma skin cancers arise worldwide annually. The detection and classification of skin cancer in early stage of development allow patients to have proper diagnosis and treatment. The goal of this article is to present a novel deep learning internet of health and things (IoHT) driven framework for skin lesion classification in skin images using the concept of transfer learning. In proposed framework, automatic features are extracted from images using different pretrained architectures like VGG19, Inception V3, ResNet50, and SqueezeNet, which are fed into fully connected layer of convolutional neural network for classification of skin benign and malignant cells using dense and max pooling operation. In addition, the proposed system is fully integrated with an IoHT framework and can be used remotely to assist medical specialists in the diagnosis and treatment of skin cancer. It has been observed that performance metric evaluation of proposed framework outperformed other pretrained architectures in term of precision, recall, and accuracy in detection and classification of skin cancer from skin lesion images.
Neuropsychiatric symptom profiles ofcommunity‐dwellingpersons living with dementia: Factor structures revisited
Authors: Regier Natalie G. , Hodgson Nancy A. , Gitlin Laura N.
Published: May 2020

Objectives

Most persons living with dementia (PLWD) will develop neuropsychiatric symptoms (NPS) at some point. NPS are often clustered into subsyndromes with other related symptoms, but the evidence supporting commonly used clusters is insufficient. We reexamine behavioral clusters in community‐dwelling PLWD and identify associated risk factors and potential contributors.

Methods

This study used baseline data from a longitudinal behavioral intervention study of 250 community‐dwelling older adults with dementia and their caregivers. Using exploratory factor analysis (principal component analysis [PCA]), the factor structure of NPS frequency scores of the Neuropsychiatric Inventory (NPI‐C) was evaluated. Multiple linear regressions assessed the association of the derived behavioral clusters with caregiver burden, caregiver depression, and quality of life of the PLWD.

Results

PCA yielded eight behavioral clusters (factors): 1 = Aggression/Rejection of Care, 2 = Apathy/Withdrawal, 3 = Restlessness/Agitation, 4 = Anxiety, 5 = Impulsivity/Disinhibition, 6 = Psychosis, 7 = Circadian Disturbance, and 8 = Depression. In multiple linear regressions, caregiver burden was significantly influenced by the anxiety cluster, caregiver depression was significantly influenced by the apathy/withdrawal cluster, and quality of life of the PLWD was significantly associated with the anxiety and circadian disturbance clusters.

Conclusions

Our eight derived behavioral clusters suggest that commonly accepted clusters of NPS may not reflect the clinical reality for community‐dwelling PLWD. Behavioral clusters appear to differentially impact and put caregivers and PLWD at risk such that personalized intervention strategies are warranted. J Am Geriatr Soc 68:‐, 2020.
What are the psychosocial consequences when fear of falling starts or ends? Evidence from an asymmetric fixed effects analysis based on longitudinal data from the general population
Authors: Hajek André , König Hans‐Helmut
Published: May 2020

Objectives

The purpose of this study was to identify whether the onset and the end of fear of falling (FOF) are associated with psychosocial consequences (in terms of depressive symptoms, loneliness, social isolation, autonomy, and subjective well‐being).

Methods/Design

Longitudinal data for this study were taken from the nationally representative German Ageing Survey which included community‐dwelling individuals ≥40 years (wave 5 and wave 6). Psychosocial outcome measures were assessed using widely established and well‐validated scales. The presence of FOF was used as the main explanatory variable. It was adjusted for age, family status, labor force participation, self‐rated health, physical functioning, as well as the number of chronic conditions.

Results

Linear fixed effects regressions revealed that FOF was associated with adverse psychosocial outcomes (increased depressive symptoms, lower life satisfaction, lower positive affect, higher negative affect, and lower perceived autonomy). Asymmetric fixed effects regressions analysis showed that the onset of FOF was associated with reduced life satisfaction as well as reduced autonomy, whereas the end of FOF was associated with reduced depressive symptoms, decreased loneliness scores, as well as decreased negative affect.

Conclusions

The study findings suggest that future studies should analyze the consequences of FOF differently (onset and end of FOF) which has practical important implications. More specifically, while strategies to avoid the onset of FOF may help to maintain satisfaction with life and autonomy, strategies to end FOF may contribute to avoid increased loneliness, feelings of negative affect, as well as increased depressive symptoms. J Am Geriatr Soc 68:‐, 2020.
How are high burden countries implementing policies and tools for latent tuberculosis infection? A survey of current practices and barriers
Authors: Faust Lena , Ruhwald Morten , Schumacher Samuel , Pai Madhukar
Published: May 2020

Background and aims

Despite the World Health Organization (WHO)'s updated guidelines on tuberculosis (TB) preventive treatment, the scale‐up of TB preventive therapy remains low in many high‐burden countries (HBCs). We conducted a survey to better understand the current status of policy implementation and barriers for scale‐up.

Methods

Survey questions pertained to HBCs' current latent TB infection (LTBI) screening and treatment strategies, and the availability of LTBI tests and newer treatments (eg, isoniazid/rifapentine [3HP]). The 19‐question survey was piloted and sent out via email in June 2019 as a protected Microsoft Word document to contacts [National TB Program (NTP) staff, researchers, and health officials] in the 30 TB HBCs. Responses were accepted until February 2020.

Results

Thirty‐seven completed surveys from 24 HBCs were received. Respondents from five countries (Brazil, Lesotho, Mozambique, Russia, Zambia) reported having LTBI guidelines that are fully implemented. Among respondents who indicated their country currently has no LTBI guideline implementation (Angola, China, DRC, India, Indonesia, Kenya, Myanmar), the most often cited barrier to implementation was the prioritization of active TB over LTBI management (n = 5, Angola, China, DRC, India, Kenya). Of the 16 countries in which respondents reported using purified protein derivative (PPD), 9 reported having experienced a PPD shortage within the past year (from time of survey). Respondents from six countries reported currently using Interferon‐gamma Release Assays (IGRAs) in their NTP, and 13 cited high cost as a barrier to IGRA use. Lastly, rifapentine was stated not be available in 8 HBCs.

Conclusion

This survey indicates limited implementation of WHO LTBI guidelines in HBCs and provides some insight into barriers to implementation, including shortage of products (eg, PPD), high costs (eg, IGRAs), and lack of regulatory approval of newer treatments (eg, rifapentine). Thus, we should work towards price reductions for LTBI tests and treatments, and the development of tests that can be more easily implemented at peripheral healthcare levels.
Recent advances in organic‐based materials for resistive memory applications
Authors: Li Yang , Qian Qingyun , Zhu Xiaolin , Li Yujia , Zhang Mayue , Li Jingni , Ma Chunlan , Li Hua , Lu Jianmei , Zhang Qichun
Published: May 2020

With the rapid development of data‐driven human interaction, advanced data‐storage technologies with lower power consumption, larger storage capacity, faster switching speed, and higher integration density have become the goals of future memory electronics. Nevertheless, the physical limitations of conventional Si‐based binary storage systems lag far behind the ultrahigh‐density requirements of post‐Moore information storage. In this regard, the pursuit of alternatives and/or supplements to the existing storage technology has come to the forefront. Recently, organic‐based resistive memory materials have emerged as promising candidates for next‐generation information storage applications, which provide new possibilities of realizing high‐performance organic electronics. Herein, the memory device structure, switching types, mechanisms, and recent advances in organic resistive memory materials are reviewed. In particular, their potential of fulfilling multilevel storage is summarized. Besides, the present challenges and future prospects confronted by organic resistive memory materials and devices are discussed.

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Electrochemical codeposited polypyrrole–tungsten oxide composite materials with wide potential windows
Authors: Bai Minghua , Li Yidi , Liu Rui , Yu Zhan , Wang Ying , Zhao Zhen
Published: May 2020

The three‐dimensional morphology has sufficient interface contact and can be in favor of the electronic transport process. In this work, the demand for high‐performance electrodes such as energy storage devices has been designed. Polypyrrole and tungsten oxide composite materials (PPy‐WO3) have been synthesized by cyclic voltammetry (CV) technology at −0.6 to 0.9 V versus saturated calomel electrode (SCE) for 20 cycles. The PPy‐WO320 mV/s, PPy‐WO360 mV/s, and PPy‐WO3120 mV/s electrodes have been prepared by CV technology at sweep rates of 20, 60, and 120 mV/s. The influences of scan rate on morphologies and charge storage properties of the composites are discussed. Among them， a three‐dimensional flake structure for PPy‐WO320 mV/s with a size of up to several micrometers was synthesized. PPy‐WO320 mV/s composites as electrode materials exhibit a wide charge storage potential window of 1.4 V (between −0.9 and 0.5 V vs. SCE) and a specific capacitance of 145.13 F/g at 1 mA/cm2. Moreover, the long‐term stability of PPy‐WO320 mV/s and PPy has been investigated in 5 M LiCl aqueous electrolyte. The stability of the materials can be improved by inorganic and organic composites.
Deza graphs with parameters (v,k,k−2,a)
Authors: Kabanov Vladislav V. , Shalaginov Leonid
Published: May 2020

A Deza graph with parameters is a ‐regular graph on vertices in which the number of common neighbors of two distinct vertices takes one of the following values: or , where . In the previous papers Deza graphs with were characterized. In this paper, we characterize Deza graphs with .
Contrast Medium or No Contrast Medium for Prostate Cancer Diagnosis. That Is the Question
Authors: Padhani Anwar R. , Schoots Ivo , Villeirs Geert
Published: May 2020

The benefits and drawbacks of the dynamic contrast‐enhanced MRI sequence for prostate cancer diagnosis are increasingly being recognized, with many centers adopting the biparametric (bp) MRI approach as the default initial approach. The abandonment of the routine use of contrast medium requires an assessment of the loss of diagnostic power against the gains in operational logistics, costs, time, capacity, and side effects. It is the balance of these factors weighted against the clinical priorities of patients that determines which patient groups can safely avoid dynamic contrast enhancement. Although systematic reviews and individual studies are broadly supportive of the bpMRI approach, the pathway impacts for men with suspected cancer using the bpMRI approach are still not well documented for clinical practice. Robust prospectively acquired data for bpMRI regarding biopsy avoidance, detection of clinically significant and insignificant cancers, and for increasing the precision of tumor grade and volume are needed. There is a requirement for prospective, randomized, or blinded head‐to‐head, multicenter studies, addressing the noninferiority of biopsy yields prompted by bpMRI and multiparametric MRI approaches. These studies should more precisely define patient groups where the benefits and harms of contrast enhancement are aligned to their clinical priorities. Only then can we be confident in recommending bpMRI as an initial diagnostic approach for prostate cancer diagnosis.

Level of Evidence

1

Technical Efficacy Stage

5
Distinct Eurasian climate anomalies associated with strong and weak MJO events
Authors: Song Lei , Wu Renguang
Published: May 2020

The MJO‐related tropical Indian Ocean outgoing longwave radiation anomalies display a bimodal distribution, indicating two types of MJO events. The present study distinguishes 14 strong and 16 weak MJO events during the 37 winters from 1979 to 2016 and compares the circulation and climate over the mid‐latitude Eurasia between strong and weak MJO events. Cold anomalies appear over Siberia and East Asia during strong MJO events when the MJO‐related convection is located over the tropical Indian Ocean, whereas the temperature anomalies are weak over Eurasia during weak MJO events. The cold anomalies over Eurasia in strong MJO events are associated with the development of surface anticyclonic anomalies and the accompanying northerly wind anomalies. On one hand, the enhancement of surface anticyclonic anomalies can be attributed to the poleward Rossby wave packets triggered by the MJO convection over the tropical Indian Ocean. On the other hand, the strong convective heating over the tropical Indian Ocean can induce anomalous meridional overturning circulation between the tropics and mid‐latitudes. The anomalous divergent winds associated with the convective heating can reach western Siberia and the descending branch of the vertical cell contributes to the enhancement of surface anticyclonic anomalies and northerly wind anomalies, leading to cold anomalies over Siberia and East Asia. In weak MJO events, the poleward Rossby waves are weak and anomalous meridional overturning is of limited meridional extent. As a result, the MJO‐related wind anomalies are weak and the associated temperature anomalies are small over large areas of Eurasia.
Last glacial maximum ecology and climate from terrestrial gastropod assemblages in Peoria loess, western Kentucky
Authors: Grimley David A. , Counts Ronald C. , Conroy Jessica L. , Wang Hong , Dendy Sarah N. , Nield Catherine B.
Published: May 2020

The Rocks loess section, in unglaciated western Kentucky, provides a high‐resolution environmental record during the last glacial maximum onset. The Peoria Silt (9 m thick) contains 26 terrestrial gastropod species, with up to 15 species within a single 5 cm interval. Thirteen radiocarbon ages, using shells or charcoal, range between 30 and 24.5 cal ka; younger loess has been leached or eroded. Stratigraphic shifts in gastropod assemblages imply significant cooling, particularly ~27 cal ka, as solar insolation was decreasing and the southern Laurentide Ice Sheet rapidly advancing. Midwestern to southern species (e.g.Anguispira kochi,Gastrocopta pentodon,Hawaii miniscula,Helicodiscus parallelus,Vallonia perspectiva) occur only in the lowermost Peoria Silt (~30–27 cal ka). In contrast, cold‐tolerant species (Columella alticola,Vertigo modesta, Vallonia gracilicosta)occur only in full glacial Peoria Silt (27–24.5 cal ka). Inferred mean July temperatures, from mutual climatic range methods, range from ~23 °C at 30 cal ka, cooling to ~18 °C by 26 cal ka; about 3–8 °C cooler than today (~26 °C). Superimposed on this cooling trend are multi‐centennial variations in detrital carbonate, fossil shell concentrations, palaeotemperature estimates, and oxygen isotope values (Vertigo,Discus, Helicodiscus). The finer‐scale variations imply relatively synchronous fluctuations in glacial sediment supply, loess sedimentation, and climate.
The development of microfinance in Cameroon: Focus on regulation
Authors: Singhe Steffi Sandra , Louche Céline
Published: May 2020

While the microfinance regulations in Cameroon have a positive influence in professionalizing the microfinance sector, it seems to have also created hurdles for MFIs to fulfill their social mission of financial inclusion. The evolution of activities of the microfinance sector over the years led to changes in the regulatory environment through the establishment of new regulations that progressively professionalize the sector and controlled certain derives. Financial inclusion has been hindered by insufficient supervision and tight regulations in terms of board members' qualifications, loan documentation requirements, and provisioning and liquidity requirements. Regulations still need to reflect more the specificities of the microfinance sector and be matched with adequate supervision in order to achieve its dual role of financial inclusion and safeguarding the financial system.
Women's entrepreneurship and social capital: Exploring the link between the domestic sphere and the marketplace in Pakistan
Authors: Khan Muhammad Salman
Published: May 2020

Research on the social capital of women entrepreneurs in contexts characterized by gender segregation between men's and women's trading spaces is underdeveloped. The literature on women's entrepreneurship and the marketplace in Pakistan is one such example. This article contributes to the literature on the social capital of female entrepreneurs from a critical perspective by drawing on an exploratory case study of women's entrepreneurship and entrepreneurial networks in the Malakand District of the Khyber Pakhtunkhwa province of Pakistan. Women's social capital was found to play a crucial role in the survival and expansion of their business activities by facilitating access to the men's trading sphere of the marketplace. It was also found that women exercise active agency in developing cross‐gender economic networks but do so in ways that do not overtly challenge social norms.
Women on audit committees and the relationship between related party transactions and earnings management
Authors: Jalan Akanksha , Badrinath S. G. , Al‐Gamrh Bakr
Published: May 2020

Our results indicate a negative relationship between related‐party transactions (RPT) and earnings management, but a significantly positive relationship between discretionary accruals and the presence of a woman chairing the audit committee. While we observe a positive relationship between RPT volume and earnings quality, we fail to find any relationship between other audit committee characteristics and the latter. One significant result in the article is the positive relation between promoter presence on the audit committee and poor earnings quality. This article documents, for the first time, such a relationship from the perspective of an audit committee, at least in the Indian context.
An exclusive kinetic model for the methylcyclohexane dehydrogenation over alumina‐supported Pt catalysts
Authors: Akram Muhammad S. , Aslam Rabya , Alhumaidan Faisal S. , Usman Muhammad R.
Published: May 2020

The experimental data of six different types of Pt‐containing alumina catalysts are used to study the detailed and rigorous kinetics of the methylcyclohexane dehydrogenation reaction. A large number of kinetic rate equations were formulated using the power law kinetics and the Langmuir‐Hinshelwood‐Hougen‐Watson (LHHW) kinetics, which were tested against the experimental data. For each catalyst, the elementary reaction step “the loss of first molecular hydrogen” in the LHHW single‐site surface reaction mechanism was observed to be the rate‐determining step. The form of the kinetic rate model developed in the study is believed to be applicable to any Pt‐loaded alumina catalyst.
Regional variation in δ13C of coral reef macroalgae
Authors: Lovelock Catherine E. , Reef Ruth , Raven John A. , Pandolfi John M.
Published: May 2020

Macroalgae are important components on coral reefs that underpin food webs but are also indicators of declines in coral reef condition. The sensitivity of macroalgal communities to environmental factors, including climate and pollutants from the land, is important for the future state of coral reefs. We assessed regional variation in the photosynthetic physiology of macroalgae on the Great Barrier Reef and Moreton Bay, Queensland, Australia, using δ13C, tissue chemistry, and metabolic indicators over broad environmental gradients from six sites spanning 13° of latitude and varying distance from shore. Our data set included 568 samples from 54 genera and 19 macroalgal orders. The δ13C of tissues had a strong taxonomic basis (explaining 66% of the variation in δ13C), varying significantly among algal orders. Particularly low values of δ13C, indicating direct use of CO2(aq) in photosynthesis, were mainly associated with lineages within the Rhodophyta. We observed declines in δ13C with increasing depth (inshore only) and latitude, from offshore to inshore sites and with increasing tissue N and N : P ratio. Variation in δ13C of tissues among macroalgal lineages suggests evolution of a range of CO2 acquisition pathways. Patterns in δ13C availability are most consistent with higher availability of CO2(aq) in cooler water and inshore sites. δ13C in macroalgae could provide an important tool for monitoring changes in CO2(aq) with increasing atmospheric CO2, with changes in ocean circulation and with changes to runoff from the land to the coastal oceans.
A Desch–Schappacher perturbation theorem for bi‐continuous semigroups
Authors: Budde Christian , Farkas Bálint
Published: May 2020

We prove a Desch–Schappacher type perturbation theorem for one‐parameter semigroups on Banach spaces which are not strongly continuous for the norm, but possess a weaker continuity property. In this paper we chose to work in the framework of bi‐continuous semigroups. This choice has the advantage that we can treat in a unified manner two important classes of semigroups: implemented semigroups on the Banach algebra of bounded, linear operators on a Banach space E, and semigroups on the space of bounded and continuous functions over a Polish space induced by jointly continuous semiflows. For both of these classes we present an application of our abstract perturbation theorem.
A novel on water environment monitoring method based on millimeter wave radiometric characteristics
Authors: Li Shan , Zhang Guang‐Feng , Gao Yuan
Published: May 2020

Aiming at the increasingly serious water pollution problem, this article proposes a floating waste monitoring method based on the characteristics of millimeter wave radiation. The method is based on the basic principles of microwave radiation and the radiometric characteristics of floating wastes. In this method, we establish a multilayer media model of floating wastes and get the radiometric temperature of different pollutants. The database of wastes based on radiometric temperature of water surface has been proposed and established. Simulation and experimental show that there is a significant difference between the floating wastes and the surface water radiometric temperature, which can be distinguished different pollutants through contrast and achieved the purpose of environmental monitoring.
NMR spectroscopy goes mobile: Using NMR as process analytical technology at the fume hood
Authors: Lee William G. , Zell Mark T. , Ouchi Takashi , Milton Mark J.
Published: May 2020

Nuclear magnetic resonance (NMR) is potentially a very powerful process analytical technology (PAT) tool as it gives an atomic resolution picture of the reaction mixture without the need for chromatography. NMR is well suited for interrogating transient intermediates, providing kinetic information via NMR active nuclei, and most importantly provides universally quantitative information for all species in solution. This contrasts with commonly used PAT instruments, such as Raman or Flow‐infrared (IR), which requires a separate calibration curve for every component of the reaction mixture. To date, the large footprint of high‐field (≥400 MHz) NMR spectrometers and the immobility of superconducting magnets, coupled with strict requirements for the architecture for the room it is to be installed, have been a major obstacle to using this technology right next to fume hoods where chemists perform synthetic work. Here, we describe the use of a small, lightweight 60 MHz Benchtop NMR system (Nanalysis Pro‐60) located on a mobile platform, that was used to monitor both small and intermediate scale Grignard formation and coupling reactions. We also show how low field NMR can provide a deceptively simple yes/no answer (for a system that would otherwise require laborious off‐line testing) in the enrichment of one component versus another in a kilogram scale distillation. Benchtop NMR was also used to derive molecule specific information from Flow‐IR, a technology found in most manufacturing sites, and compare the ease at which the concentrations of the reaction mixtures can be derived by NMR versus IR.
The effects of concentric and eccentric training in murine models of dysferlin‐associated muscular dystrophy
Authors: Begam Morium , Roche Renuka , Hass Joshua J. , Basel Chantel A. , Blackmer Jacob M. , Konja Jasmine T. , Samojedny Amber L. , Collier Alyssa F. , Galen Sujay S. , Roche Joseph A.
Published: May 2020

Introduction

Dysferlin‐deficient murine muscle sustains severe damage after repeated eccentric contractions.

Methods

With a robotic dynamometer, we studied the response of dysferlin‐sufficient and dysferlin‐deficient mice to 12 weeks of concentrically or eccentrically biased contractions. We also studied whether concentric contractions before or after eccentric contractions reduced muscle damage in dysferlin‐deficient mice.

Results

After 12 weeks of concentric training, there was no net gain in contractile force in dysferlin‐sufficient or dysferlin‐deficient mice, whereas eccentric training produced a net gain in force in both mouse strains. However, eccentric training induced more muscle damage in dysferlin‐deficient vs dysferlin‐sufficient mice. Although concentric training produced minimal muscle damage in dysferlin‐deficient mice, it still led to a prominent increase in centrally nucleated fibers. Previous exposure to concentric contractions conferred slight protection on dysferlin‐deficient muscle against damage from subsequent injurious eccentric contractions.

Discussion

Concentric contractions may help dysferlin‐deficient muscle derive the benefits of exercise without inducing damage.
Methanol erschnüffeln
Authors: van den Broek Jan , Güntner Andreas
Published: May 2020

Bisher gab es keine praktikable Methode, eine Methanolvergiftung in Minutenschnelle zu diagnostizieren. Ein kürzlich entwickelter Gassensor erlaubt dies nun mit einem einzigen Atemstoß. Der Detektor passt auf eine Handfläche und erkennt Methanol auch in gepanschtem Schnaps.
Kupferspuren im Gletscher
Authors: Eichler Anja , Kellerhals Thomas , Schwikowski Margit
Published: May 2020

Gletschereis speichert Stoffe aus der Luft über Jahrtausende. Die Analyse der Eisbohrkerne aus den Anden hilft dabei, den Beginn der Kupferverhüttung in Südamerika zu enträtseln.
Von der Rohware zum Riegel: Bitter ist nicht nur die Bohne
Authors: Leusmann Eliza
Published: May 2020

Seit Anfang des Jahres 2019 ist geregelt, wie viel Cadmium Kakaoprodukte enthalten dürfen. Aber woher kommt das Cadmium eigentlich? Was Kakaobauern tun können und ob das neue Gesetz ein Problem für Schokoladenhersteller ist.
Trendbericht Physikalische Chemie: Kalte Reaktionsdynamik unter Kontrolle
Authors: Osterwalder Andreas
Published: May 2020

Mit Molekularstrahlexperimenten lassen sich einige der grundlegendsten Fragen der Chemie beantworten, nämlich ob und wie sich die exakte Konformation eines reaktiven Molekülpaars auf den Ausgang der Reaktion auswirkt.
Bilanz Roche
Authors: Bulmahn Maren
Published: May 2020

Das Schweizer Unternehmen Roche hat im Jahr 2019 bei Umsatz und Gewinn zugelegt. Mehr als zwei Drittel davon stammen in Deutschland von Medikamenten, das Übrige aus der Diagnostikasparte.
Bilanz Borealis
Authors: Bulmahn Maren
Published: May 2020

Der Kunststoffhersteller Borealis ist bald zu mehr als der Hälfte in österreichischer Hand. Die Umsätze blieben im Jahr 2019 etwa so wie im Vorjahr.
Von den Lahnbergen zum Hönggerberg …
Authors: Wagner Mona
Published: May 2020

In Marburg ist Mona Wagner in die Welt der Chemie eingetaucht. Nach ihrem Studium ist sie im Jahr 2015 zum Promovieren an die ETH Zürich gewechselt – und dort läuft vieles anders, als sie es aus Deutschland kannte.
… und von dort an den Aasee
Authors: Häfliger Joel
Published: May 2020

Joel Häfliger, Jahrgang 1995, ist zum Promovieren von der ETH Zürich an die Universität Münster gewechselt und überzeugt, die für ihn einzig richtige Entscheidung getroffen zu haben.
Reindeer feeding ecology and hunting strategies by Magdalenians from Pincevent (Paris Basin, France): New insights from dental microwear textural analyses
Authors: Catz Natacha , Bignon‐Lau Olivier , Merceron Gildas
Published: May 2020

In Pincevent (Paris Basin), archeaozoologists have observed a variation of hunting strategies between Magdalenian levels IV0 and IV20. Previous works on human‐prey interaction showed that hunters modelled their behaviour on their prey; therefore, reconstructing animal behaviour in order to reconstruct human strategies could enable better interpretation of these levels. This study aims to contribute to a global understanding of the variation between these level's hunting strategies using microwear texture analysis. This proxy, which can be used to reconstruct diet, will enable to detect changes in the behaviour pattern of the prey. The decision was made to focus this study on reindeer (Rangifer tarandus) as it was one of the two most exploited resources on this site, alongside horses. The enamel surface of teeth from two populations of reindeer, hunted and found in levels IV0 and IV20, showed a variation of diet between levels. Environmental and ecological matters are discussed with an aim to understanding this variation of behaviour in reindeer populations and highlight a change of strategic behaviour among hunters.
Risk of incident dementia following metformin initiation compared with noninitiation or delay of antidiabetic medication therapy
Authors: Salas Joanne , Morley John E. , Scherrer Jeffrey F. , Floyd James S. , Farr Susan A. , Zubatsky Max , Barthold Doug , Dublin Sascha
Published: May 2020

Purpose

Emerging evidence suggests metformin compared with sulfonylurea is associated with an 8% to 10% lower risk for dementia. Guidelines recommend metformin as initial diabetes treatment, but there is still the question of treatment timing. Thus, the risk of dementia associated with initiating metformin compared with not initiating or delaying treatment was examined.

Methods

A retrospective cohort study (1996 to 2015) was conducted with electronic health records from Veteran Health Affairs (VHA; n = 112 845) and Kaiser Permanente Washington (KPW; n = 14 333) healthcare systems. Patients were aged ≥50 years, had a hemoglobin A1c (HbA1c) between 6.5 and <9.5 mg/dL, and did not have dementia or fills for antidiabetic medications before cohort entry. Initiators started metformin monotherapy and noninitiators used no antidiabetic medications in the 6 months after the first qualifying HbA1c. The primary outcome was incident dementia. Propensity scores and inverse probability of treatment weighting (IPTW) controlled for confounding in Cox proportional hazards models.

Results

During a median follow‐up of 6.2 years in VHA and 6.8 years in KPW, there were 7547 new dementia cases in VHA and 1090 in KPW. After IPTW, there was no association between initiation of metformin (vs no initial treatment) and incident dementia in VHA (HR = 1.04; 95% confidence interval [CI]: 0.95‐1.13) or KPW (HR = 0.81; 95% CI: 0.51‐1.28). Results did not differ by age, baseline HbA1c, or race.

Conclusions

Results do not support initiating metformin earlier to prevent cognitive decline and, thus, may dampen enthusiasm for metformin as a potential antidementia drug. Randomized clinical trials could help clarify the relationship between metformin and cognitive decline.
Sleep‐disordered breathing and markers of morbidity in children and adolescents with cystic fibrosis
Authors: Barbosa Roberta Ribeiro Batista , Liberato Fernanda Mayrink Gonçalves , de Freitas Coelho Pitiguara , Vidal Pâmela dos Reis , de Carvalho Roberta Barcellos Couto Olimpio , Donadio Márcio Vinícius Fagundes
Published: May 2020

Background

Studies have shown that sleep disorders occur in cystic fibrosis (CF) patients and may be present before daytime clinical manifestations.

Objectives

To evaluate the presence of sleep disorders among children and adolescents with CF, attempting to identify associations with pulmonary function, nutritional status, days in hospital, and days taking antibiotics.

Methods

Individuals with a diagnosis of CF aged between 6 and 18 years were included. Information on sociodemographic, clinical profile, history of hospitalizations, and use of antibiotics in the last year were collected. Spirometry, bioimpedance, and polysomnography were performed. The presence of nocturnal hypoxemia and obstructive sleep apnea syndrome (OSAS) were evaluated and participants divided according to their presence.

Results

Thirty‐one patients were included. The prevalence of OSAS was 32.3% and nocturnal hypoxemia was 29.0%. Average nocturnal peripheral oxyhemoglobin saturation (SpO2) correlated (P < .001) with forced vital capacity (r = .55) and forced expiratory volume in the first second (r = .62). The higher the percentage of total sleep time (TST) with SpO2 less than 90%, the lower the pulmonary function. Individuals with OSAS and nocturnal hypoxemia had lower spirometric values compared to patients without these disorders, but the nocturnal hypoxemia group also had lower Shwachman‐Kulczycki score, longer hospitalization time and antibiotic use. TST with SpO2 less than 90% was associated with length of hospitalization (r2 = .53).

Conclusion

Children and adolescents with CF have sleep disorders, including OSAS (32.3%) and nocturnal hypoxemia (29%). Individuals with nocturnal hypoxemia presented lower lung function, worse clinical score, and higher morbidity. TST with SpO2 less than 90% was associated with length of hospitalization.
The Influence of Blood Collection Tubes in Biomarkers’ Screening by Mass Spectrometry
Authors: Zhang Siyuan , Zhao Zixuan , Duan Wenjing , li Zhaoxin , Nan Zhuhui , Du Hanzhi , Wang Mengchang , Yang Juan , Huang Chen
Published: May 2020

Purpose

Mass spectrometry is one of the rapidly developing bio‐analytical techniques in recent years, and it shows that the results of biomarkers’ screening can be influenced by pre‐analytical process. The selection of the blood collection tubes is one of the most significant steps of pre‐analytical process which is often neglected by researchers. So, it is urgent to define the influence of blood collection tubes clearly in biomarkers’ screening.

Experimental Design

Two types of blood collection tubes, non‐additive tubes and coagulant activator tubes, are used to collect serum samples from patients and healthy controls. All samples are analyzed using matrix‐assisted laser desorption ionization‐time of flight mass spectrum in this study.

Results

The serum protein profile changes while using coagulant tubes whether for patients or healthy controls. It is found that the effect of coagulant on serum protein of patients is smaller than that of control group. There are 27 significantly different peaks between the control group and the control coagulant group. However, between patient group and patient coagulant group, only one differential peak is obtained. Coagulant changes the expression differences between patients and healthy controls, making the differences expand, shrink or reverse, and most of the polypeptides are small molecule, which will change the results of biomarker's screening.

Conclusions and Clinical Relevance

This research suggested that different types of blood collection tubes would influence the final laboratory results. So it's important for clinicians to choose the proper tubes to detect biomarkers and make correct diagnoses.