bluuebunny/crossref_metadata_2025 huggingface dataset:
Derivable Equations and Issues Often Ignored in the Original Michaelis-Menten Mathematical Formalism
Authors: I. Udema Ikechukwu
Published: December 2019

Background: There has been recent shift from the core issue of Michaelian kinetics to issues regarding various kinds of quasi-steady-state assumptions. Derivable equations with which to determine reverse rate constant for the dissociation of enzyme-substrate complex (ES) is given less attention.

Objectives: The objectives of this research are: 1) to derive other equations from differential equations whose evaluation leads to MM equation and 2) quantify based on derived equations the kinetic parameters given less attention and duration of catalytic events.

Methods: A major theoretical research and experimentation using Bernfeld method.

Results and Discussion: The durations for ES dissociation (ESD) into free substrate, S and enzyme, E were much shorter than the duration of ESD into E and product, P in 3 minutes duration of assay with low [S]; it was the shortest and longest in 3 and 5 minutes durations respectively with high [S]. The durations of ESD into E and P was shortest in 3 minutes duration of assay with high [S]. The values of reverse rate constant, k-1 for ESD into S and E in 3 minutes duration of assay with high [S] was » the rate constant, k2 for product formation and they are much higher than in other duration of assay.

Conclusion: The equations for the determination of the durations of various events, in a given catalytic cycle were derived. The various time regimes for each event and the rate constant for the dissociation of the ES can be graphically and calculationally determined as the case may be. Substrate concentration regime and duration of assay affects rate constants.
The Morphology of Re-epithelized Skin Following Experimental Open Wound in Wistar Rat Treated with Vitellaria paradoxa Oil
Authors: Adedeji Abiodun Oluwabusola , Orisadiran Patrick Kunle , Abdulrahman Abdulfatai , Adenowo Thomas Kehinde
Published: December 2019

Aims: The present study assessed the morphology of re-epithelized skin following experimental open wound in rat model treated with Vitellaria paradoxa oil.

Place and Duration of Study: Anatomy Department, Olabisi Onabano University, Ago Iwoye and Biochemistry Department, Ladoke Akintola University of Technology, Ogbomoso, Nigeria between June, 2018 and March, 2019.

Methodology: Excision wounds were surgically created on three groups of ten rats each (II-IV). Group I was assigned as normal control (no surgery), Group II was treated with Vitellaria paradoxa oil, Group III was treated with Dermazin and Group IV was treated with distilled water. Area (cm3) of the wound were measured on days 3, 6 and 9, the rate of wound healing, re-epithelization of the skin were assessed histologically while the thickness of the granular cells layer and the organization of the epidermal squamous cells were evaluated morphologically, the level of collagen was determined in the wounds treated with Vitellaria paradoxa oil and compared with the collagen level in wound treated with distilled water and dermazin.

Results: The wound areas significantly (P < 0.05) reduced in V. paradoxa oil treated group indicating the comparative efficacy of V. paradoxa oil. Histological observations indicated gradual and complete re-epithelization of the skin in Vitellaria paradoxa oil treatments group. Increased in collagen deposition in V. paradoxa oil treated group is also observed (P < 0.05).

Conclusion: The results of this morphology indicated that V. paradoxa oil is a good potential in re-epithelization of open wound with no clinical disadvantage such as body weight, rectal temperature, packed cell volume using rats as animal model.
Statistical Analysis of Students’ Feedback with the Services of the on Campus Boy’s Hostels: A Case Study of Mehran University, Jamshoro
Authors: Memon Muteeullah , Ahmed Shahzaib , Waleed Muhammad , Ali Korejo Kazim , Ahsan Qadeer Muhammad
Published: December 2019

Currently, the hostel life is so necessary for the students. During their higher studies, the students face a lot of problems of accommodation. After the solution of accommodation, the students face the issues in the hostels regarding their provided services. The data of students’ feedback is gathered from the Director MIS, MUET, Jamshoro by taking the sample of 60 students from each boy’s hostel. For analysis, we use the tool Statistical Package for Social Sciences (SPSS V.16). This study revealed the analysis of two services, water supply and first aid in the seven boy’s hostels of MUET, Jamshoro. The null hypothesis is accepted for all hostels except Rashidi, Hyder Bux Jatoi and Shah Abdul Latif. These results determined the strong relationship between the services water supply and first aid. From this study, we suggest to authorities of the university management to provide the necessary betterment regarding the water supply and first aid facilities in Rashidi, Hyder Bux Jatoi and Shah Abdul Latif hostels.
Phenotypic and Molecular Characterization of Endophytic Bacteria Isolated from Banana
Authors: Ragavi G. , Muthamilan M. , Nakkeeran S. , Kumaravadivel N. , Sivakumar U. , Suganthi A.
Published: December 2019

Several species of endophytic bacteria has been reported from various plants. In the present study, samples of roots, rhizome, pseudostem, petiole and leaves of healthy Banana plant were collected from variety Yangambi km5 (AAA). In total, 38 endophytic bacteria were isolated. Amongst 16 isolates were selected based on compatibility by cross streak method. The 16 strains tested by paper disc method, Lf4, Lf5, Lf10, Pt4 and Ps7 showed inhibitory effects against Pectobaterium carotovorum subsp. carotovorum under in vitro conditions. The Lf4 and Lf5 showed similar results for the biochemical characteristics studied. The isolate Lf10 showed a slight difference with regard to oxidase test, Methyl red, Urease test and H2S production. The isolates Pt4 and Ps7 showed similar result except nitrate reduction, KOH test and Pigment production. Bacillus subtilis (Bs) strain (culture collected from Department of Plant pathology, TNAU) was used as reference culture. The total DNA extracted from selected five isolates was identified by partial sequencing of the 16S rRNA gene and phylogenetic tree was constructed using MEGA 6.0. The results confirmed that isolates Lf4 and Lf5 were Bacillus subtilis, isolate Lf10 was an Ochrobactrum daejeonense, isolate Pt4 was an Achromobacter xylosoxidans and Ps7 was a Pseudomonas aeruginosa. The study revealed that all the five strains have biocontrol potential against soft rot pathogen.
Shelf Life Extension of Banana (Musa spp.) using Hexanal Formulation as a Post-harvest Dip
Authors: Muthuvel I. , Srivignesh S. , Mutharasu P. , Kavino M. , Subramanian K. S.
Published: December 2019

Postharvest dipping of fruits in hexanal formulation extends the shelf life by inhibiting enzyme phospholipase D (PLD) activity. To enhance the postharvest shelf-life and quality of different banana cultivars viz., Grand Naine (AAA), Ney Poovan (AB), Poovan (AAB) and Rasthali (AAB) were treated with different concentration of hexanal formulations (1% and 2% Enhanced fresh formulation (EFF)) and stored at atmospheric storage condition. The results indicate that the quality characteristics of 2% EFF treated fruits of Grand Naine (AAA), Poovan (AAB) and Rasthali (AAB) were low TSS, total sugars, reducing sugars and acidity indicating the perpetuation in quality of fruits during storage life besides extended shelf life of fruits. Banana fruits treated with hexanal, irrespective of cultivars experienced a significant delay in weight loss and higher firmness as compared to respective control.  The high-resolution imaging had clearly shown that the application of hexanal delayed the ripening process by the structural integrity of cells on skin and fruit pulp. The PLD enzyme activity, respiration and ethylene evolution rates (more than 10%) were markedly reduced over control due to hexanal treatment. Our results revealed that the application of hexanal formulation as postharvest dip treatment in different banana cultivars significantly enhanced shelf life over control besides continuance of quality during the storage period.
Effect of Processing on the Nutritional Composition of Moringa olifera Leaves and Seeds
Authors: Umerah N. N. , Asouzu A. I. , Okoye J. I.
Published: December 2019

Background/Objective: Processing improves the nutritional quality of food and may/not lead to nutrient losses. Processing is done to eliminate inactive microorganisms/ antinutrients and extend the shelf life of food. Moringa oleifera plant is an important tree in some part of Nigeria having been successfully used as food, medicinal and for industrial purpose. This study was designed to determine the effect of processing on the nutritional profile of Moringa olifrera leaves and seeds.

Materials and Methods: The leaves and seeds were harvested from the forest. The leaves were washed, drained and divided into three portions. The first portion was processed raw, the sun and shade dried samples were the second and third portion. The seeds were cracked and divided into six portions. The first portion was processed raw and the other five portions were fermented for 24, 48, 72, 96 and 120 h respectively. The samples were analyzed for proximate, vitamin, mineral, and anti-nutrients contents using the standard method.

Results: The proximate composition of the seeds showed that the samples had a range of moisture, 16.63-17.75%, protein 13.92-38.45%, fat 14.93-19.00%, fibre 3.94-7.10%, ash 1.96-6.22% and carbohydrate 9.08-36.61%/100 g respectively. The ranges for the mineral contents of the seeds were iron 2.10-33.35 mg, zinc 1.19-1.35 mg/100 g, and iodine 12.33-126.61 mg. Also, the ascorbic acid content of the seeds ranged from 3.57- 24.55 mg. The anti-nutrient contents of the seeds were 0.03 – 1.35/100 g saponin, 0.21 – 6.25 mg/100 g of oxalate, 0.11 – 0.28 mg tannins and 5.69 – 16.81 mg/100 g of phytate. The proximate composition of the vegetables ranged from 8.99 – 75.33% moisture, 6.01 – 17.78% protein, 0.64 – 3.89% fat, 3.14 – 11.96% fibre, 2.46 – 15.22% ash and 12.01 – 48.52% carbohydrate. The ranges for mineral contents of the vegetables were iron 0.04 – 0.23 mg, zinc 0.03 – 0.10 mg and iodine 13.66 – 46.61 mg. The vitamin levels of the vegetables were ascorbic acid 56.43 – 167.66 mg/100 g. The level of the anti-nutrients in the vegetables ranged from 0.04 – 1.26 mg/100 g saponin, 0.31 – 8.44 mg/100 g oxalate, 0.05 – 0.20 mg/100 g tannins while phytate varied from 3.31 – 13.20 mg/100 g.

Conclusion: Processing of both leaves and seeds of Moringa olifera increased their nutrient density and reduced the concentration of anti-nutrients. The consumption of Moringa olifera should be popularized to diversify diet and extend their food use.
Glutathione and Bilirubin Concentrations as Markers of Oxidative Stress Measured among Sickle Cell Anaemia Subjects Attending University of Calabar Teaching Hospital, Calabar Nigeria
Authors: Onukak E. E. , Akwiwu E. C. , Akpotuzor J. O. , Okafor A. O. , Onukak A. E.
Published: December 2019

Aims: This study aimed at examining the oxidative stress level of sickle cell anaemia subjects using glutathione and bilirubin levels as markers as well as the red cell parameters.

Study Design: Case-control study.

Place and Duration of Study: University of Calabar Teaching Hospital, Calabar-Nigeria, between August 2018 and July 2019.

Methodology: Subjects comprised 45 SCA patients (27 females, 18 males; age range 10-45 years) attending clinic at University of Calabar Teaching Hospital Calabar, Nigeria and equal number of age and sex-matched control subjects with Hb AA. Blood samples were collected and analyzed by standard methods. The red cell parameters were analysed by automation using FY-Smart-1 auto haematology analyzer. Bilirubin assay was performed using the colorimetric method, while glutathione was performed by enzyme-linked immunosorbent assay technique.

Results: The red blood cell count, haemoglobin concentration, and haematocrit values of SCA subjects were significantly lower (p=0.001) compared to values from control subjects, while the red cell indices and red cell distribution width values were increased in SCA subjects (p=0.001). The Total bilirubin, conjugated bilirubin and unconjugated bilirubin were significantly increased (p=0.001) among SCA subjects, while the glutathione concentration values were reduced (p=0.001) when compared to values obtained from control subjects.

Conclusion: SCA subjects have marked red cell size variation, lymphocytosis and thrombocytosis. The haemolytic events that occur in sickle cell anaemia results in glutathione depletion.
Attitude, Awareness and Experience of Women towards the Breast Self-examination in Saudi Arabia
Authors: Zaidi Nisar Haider , K. Althoubaity Fatma
Published: December 2019

Objective: To evaluate the attitude, awareness and experience of Women towards the breast self-examination.

Methods: This is population-based study with the total number of the participants were 349 between 25-70 yrs of age, between December 2017 to February 2018 at King Abdulaziz University Hospital, Jeddah. A questionnaire was given to females attending the clinic or attending a lecture for breast cancer awareness.

Results: A total of 349 patients were studied. Saudi was 76.5% and non-Saudi was 23.5%. Patients less than 25 years were 26.4% and above 25 years were 73.6%. The majority were between 25 to 45 years of age which was 66.4%. The majority were married 64.5%, single 30.4%, widow 2.9% and divorced were 2.3%. 65% had children and 59.3% did lactate their kids. Use of contraceptive pills was 50.4%. Family history of breast cancer was in 18.1% and sister had breast cancer in 3.46%, aunt 3.7%, stepdaughter in 6%, grandmother in 3.2% and mother in 2% of cases. Smokers were 10.6%. Family history of other malignancy was in 9.7% with colon cancer in 6.3% and uterus in 3.4%.

History of taking herbs was in 14.6% of cases of which soya in 3.4%, baboon 2.6%, green tea 2.3%, ginger 2.3% and weight lowering herbs 1.7%. 12.3% of patient had breast biopsy and 12% had another tumour like thyroid, uterus, colon etc. 22.1% admitted that they did self- breast examination. Their source of knowledge about breast self-examination was Television in 13.5%, hospital 5.7% and doctor in 2.9%. Routine clinical examination was done in 82.2% and the reason for it was not known to the majority of them. Examination by doctors was done in 25.5% of cases. Mammography was done by 16.9%, ultrasound in 16.9%. 12.3% preferred mammography. Regarding the belief that biopsy will lead to spreading of the tumour, 16.3% said that they believe it. 3.4% believed that cancer is infective disease and 86.2% believed that breastfeeding decreases breast cancer incidence.

Conclusions: Breast self-examination is an effective tool to detect early breast cancer especially in poor and underdeveloped countries which lack resources for proper screening of breast cancer. Cultural beliefs and ritual practices may affect early detection of breast cancer.
Evaluation of Urine CCA Strips for (Field) Diagnosis of Active Schistosoma mansoni Infection in a Low Endemic Kenyan Community
Authors: Adel Ephraim Odek , O. Orinda George , T. Mwanje Mariam
Published: December 2019

Schistosomiasis is a chronic parasitic disease caused by a digenetic trematode blood fluke of the genus Schistosoma. The disease remains a serious public health problem in endemic countries and affects at least 207 million people worldwide, with 85% in Africa. In Kenya, more than 3.5 million are infected. A definite diagnosis of the disease plays a key role in the control of schistosomiasis. The detection of Schistosome Circulating antigens is an effective approach to discriminate previous exposure and current infection. Simple, non-invasive tools for detection of S. mansoni would be highly valuable with the view of post-intervention assessment in programmes but also for treatment/re-treatment of the individual patient. The study was conducted in Makueni, a low infection area (6 to 90 years old). The prevalence was 56.4% after three consecutive Kato-Katz stools. A population sample of n= 521 individuals was selected from an initial study cohort in an epidemiological follow-up of Schistosome infections in this foci. All the subjects in the sub-sample had been treated with praziquantel 40 mg/kg. The study was to determine the prevalence of S. mansoni using Kato technique and CCA (Circulating Cathodic Antigen) urine Elisa strips at baseline and 24 hours then also at 2 years later. The cohort study population at baseline had a prevalence of 62% of the schistosomiasis infection. The detection of schistosomiasis CCA at baseline using the CCA Elisa strip on urine samples gave a prevalence of 71.9%. The CCA was determined 24 hours after treatment with PZQ and the prevalence was 44.1%. In conclusion, Kitengei village is low endemic for schistosomiasis. Finally, circulating cathodic antigen can be used as a diagnostic tool, for the follow-up of chemotherapy and re-infection and as a field test and/or screening tool in control programmes.
Production Components and Agricultural Productivity of Corn under Nitrogen Doses and Planting Times
Authors: Silva Soares Marcelo Augusto da , Silva Samuel , Teodoro Iêdo , Cantarelli Arthur Luan Dias , Rodrigues Gerlan do Nascimento , Lins Cunha Jorge Luiz Xavier , Moura Ana Beatriz de Almeida , De Moura Allan Hemerson , Moura Ana Caroline de Almeida , Filho José Gomes
Published: December 2019

Aims: The objective of this study was to evaluate the best time for planting and nitrogen dose during the dry season that provides better yield to corn crop in the Alagoas Coastal Tablelands region.

Study Design: The experimental design was in randomized blocks, in the split plot scheme with four repetitions.

Place and Duration of Study: The experiment was developed at the Center of Agrarian Sciences of the Federal University of Alagoas in 2016.

Methodology: The plots consisted of 20 lines with seven meters in length and received the four sowing seasons (E1: 28/05/16, E2: 11/06/16, E3: 25/06/16, E4: 22/07/16). The subplots contained 5 lines of 7 meters each and received the nitrogen doses (0, 75, 150 and 225 kg ha-1). The variables analyzed were: Number of grains per ear (NGE), grain mass per ear (GME) and agricultural yield obtained from the weighing of all grains harvested in the useful area of each plot.

Results: The variables agricultural productivity and number of grains per ear of corn adjusted to the quadratic regression model, while for the mass of 1,000 grains the linear was better. Grain mass per cob, number of grains per cob, weight of 1,000 grains and yield are influenced by nitrogen rates. The E1 season was the one that provided the highest grain mass per turn (235 g), number of grains per ear (675) and agricultural yield (9.6 t ha-1). For the mass of 1,000 grains, season E2 obtained the highest result (263 g).

Conclusion: Maximum corn yield can be achieved by applying 209 kg ha-1 of N, which corresponds to a yield of 9.55 t ha-1 if planted until 06/11/16.
Effects of Substrate to Inoculum Ration on Biogas Production from Anaerobic Co-digestion of Office Paper and Cow Manure
Authors: Elniski Autumn R. , Chatterjee Siddharth G. , Mondal Chanchal , Doelle Klaus
Published: December 2019

Anaerobic digestion can utilize renewable resources to produce energy in the form of biogas. Cow manure inoculum contains the microorganisms needed for this application and unrecycled paper waste can be used as a substrate. The use of these feedstocks together is not well studied. Finding ideal operating parameters and modelling biogas production is vital for future integration of anaerobic digestion. The use of various models when examining anaerobic digestion is important to ensure the best models are used for future research and industrial applications. Office paper and cow manure were combined at the different substrate to inoculum ratios with a total solids content of 6% at 38.4°C for 15 days. Four models (Time-Lag, No-Lag, Modified Gompertz, and Modified Logistic) were fitted to the experimental data to find which model best represented each biogas production process. Models varied in the accuracy of their fit to the data and no single model had the lowest RMSE values for each treatment. The digester containing a paper to manure ratio of 2:1 produced the most biogas (82 mL biogas/g VS), but the 5:1 reactor had the greatest biogas production potential over a longer period based on the model parameters (maximum cumulative biogas yield and biogas production potential). More biogas was produced in this study compared to other works reported in the literature, showing that this combination of co-digestion substrates could be expanded upon in the future. New models need to be examined or developed for these systems to better represent this co-digestion process for future research and commercial applications.
Development and Evaluation of a Drip Irrigation System in Southeastern Nigeria
Authors: Nwachukwu C. P. , Orakwe L. C. , Okoye N. M.
Published: December 2019

Extreme climatic factors (temperature, precipitation etc) which at times lead to drought and flooding affect crop yield negatively. In this study, a PVC drip irrigation was developed and the irrigation parameters were evaluated in a farmland with three tillage methods (conventional tillage, conservative tillage and no tillage). The irrigation treatments comprised of three levels of irrigation (50% Management allowable depletion, 30% management allowable depletion and 10% management allowable depletion). Different irrigation parameters were evaluated for different crop growth stages, different soil treatments and different soil depths (0-25 cm, 25-50, 50-75 and 75-100 cm depths).

The field capacity was determined at -0.01MPa, from the result, the field capacity was minimum at no tillage (0.07 cm3/cm3, 0.11 cm3/cm3, 0.12 cm3/cm3, and 0.14 cm3/cm3) for soil depths 0-25 cm, 25-50 cm, 50-75 cm and 75-100 cm respectively, for conservative tillage (0.11 cm3/cm3, 0.11 cm3/cm3, 0.11 cm3/cm3, 0.14 cm3/cm3) for 0-25 cm, 25-50 cm, 50-75 cm and 75-100 cm soil depths respectively and conventional tillage (0.09 cm3/cm3, 0.13 cm3/cm3, 0.15 cm3/cm3, 0.17 cm3/cm3) for 0-25 cm, 25-50 cm, 50-75 cm and 75-100 cm soil depths respectively.

The permanent wilting point was determined at -1.5MPa, from the result, permanent wilting point increased with increase in soil depth in conventional tillage and no tillage with PWP of 0.01 cm3/cm3, 0.05 cm3/cm3, 0.09 cm3/cm3 and 0.11 cm3/cm3 at 0-25 cm, 25-50 cm, 50-75 cm and 75-100 cm soil depths respectively for conventional tillage and PWP of 0.02 cm3/cm3, 0.05 cm3cm3, 0.05 cm3/cm3 and 0.08 cm3/cm3 at 0-25 cm, 25-50 cm, 50-75 cm and 75-100 cm soil depths respectively for no tillage.

The average net irrigation was found to be 1.2 cm, 1.56 cm and 1.95 cm for conventional tillage, conservative tillage and no tillage respectively, while the average gross irrigation was found to be 1.7 cm, 1.7 cm and 2.1 cm for conventional tillage, conservative tillage and no tillage respectively.

Statistical analysis of net and gross irrigation gave a coefficient of determination of 0.99 and p-value at 0.05 was significant with a value of 0.00007.
Attitudes Study of Students and Staff of Nursing about Euthanasia in Behbahan City, 2018
Authors: Rafi Alireza , Khalili Sanaz , Naeimi Samaneh , Akbari Fakhridokht , Moradi Najmeh , Jamshidi Zeinab , Hadi Fereshteh , Mohseni Leila Amir , Karami Azam
Published: December 2019

Introduction: Nursing students are part of a clinical teaching team in the course of education. And it is important to examine their attitude toward euthanasia. Investigating the attitude of nursing students towards euthanasia has always been welcomed by researchers. These studies often indicate a lack of acceptance of euthanasia among nurses, but different percentages of opposition to euthanasia have been reported. This study aimed to determine the attitudes study of students and staff of nursing about euthanasia in Behbahan city in 2018.

Materials and Methods: This descriptive-analytical study was conducted to investigate the euthanasia attitude among nursing staff and students in 2018. The study population is nurses and nursing students of Behbahan city. Population volume was 187 in Behbahan hospital staff and 117 students respectively, that with Cochran's formula with 95% confidence interval was 126 and 83 respectively (z: equal 1.96 p=q=0.5 d=0.5). Students were selected from semesters 4 to 8 in order to understand students correctly. Data were analyzed by SPSS software version 22 and statistical methods including: mean, frequency, T-test, Chi-Square, multiple regression test and significance level p <0.05 was used.

Results: 107 nurses and 83 nursing students participated in this study. The mean age of participants was 27 years. Multiple regression was used to examine the relationship between the dimensions of euthanasia and demographic variables. Multiple regression results showed that naturalistic beliefs were significantly different between the two groups of nurses and students (p-value = 0.021). There was no significant difference between other aspects of euthanasia attitude in nurses and students. There were also significant differences between the two groups of men in terms of practical considerations (p-value=0.048).

Conclusion: Knowing the attitudes of nurses in a community towards the issue of euthanasia can be an effective step towards a better plan for improving the care of patients with euthanasia. The results of this study showed that naturalistic beliefs were significantly different between the two groups of nurses and students. But there was no significant difference between other aspects of euthanasia attitude and nurses and students; There were also significant differences in the practical considerations between the two groups of men. It is necessary to improve the knowledge of nurses in this field.
Decapentaplegic signaling regulates Wingless ligand production and target activation during Drosophila wing development
Authors: Li Yunlong , Zhang Fengchao , Jiang Na , Liu Tong , Shen Jie , Zhang Junzheng
Published: December 2019

The Decapentaplegic (Dpp) and Wingless (Wg) signaling pathways are essential for animal development. However, how these two signals are integrated in distinct tissues is not fully understood. Here, we describe a novel mode of Dpp‐Wg crosstalk during Drosophila wing development. We show that the canonical Dpp signaling is required for Wg target gene activation. In addition, Dpp signaling inhibits the transcription of wg through the schnurri (shn) repressor complex. A Dpp‐responsive shn/pMad/Med silencer element (SSE) is identified in the genomic loci of the wg gene. ChIP analysis suggests that shn interacts with this element in vivo. Our findings support a model in which Dpp signaling plays a dual role in transcriptional regulation of both the wg gene and downstream targets.
RARS1‐related hypomyelinating leukodystrophy: Expanding the spectrum
Authors: Mendes Marisa I. , Green Lydia M. C. , Bertini Enrico , Tonduti Davide , Aiello Chiara , Smith Desiree , Salsano Ettore , Beerepoot Shanice , Hertecant Jozef , von Spiczak Sarah , Livingston John H. , Emrick Lisa , Fraser Jamie , Russell Laura , Bernard Genevieve , Magri Stefania , Di Bella Daniela , Taroni Franco , Koenig Mary K. , Moroni Isabella , Cappuccio Gerarda , Brunetti‐Pierri Nicola , Rhee Jullie , Mendelsohn Bryce A. , Helbig Ingo , Helbig Katherine , Muhle Hiltrud , Ismayl Omar , Vanderver Adeline L. , Salomons Gajja S. , van der Knaap Marjo S. , Wolf Nicole I.
Published: December 2019

Objective

Biallelic variants in RARS1, encoding the cytoplasmic tRNA synthetase for arginine (ArgRS), cause a hypomyelinating leukodystrophy. This study aimed to investigate clinical, neuroradiological and genetic features of patients with RARS1‐related disease, and to identify possible genotype‐phenotype relationships.

Methods

We performed a multinational cross‐sectional survey among 20 patients with biallelic RARS1 variants identified by next‐generation sequencing techniques. Clinical data, brain MRI findings and genetic results were analyzed. Additionally, ArgRS activity was measured in fibroblasts of four patients, and translation of long and short ArgRS isoforms was quantified by western blot.

Results

Clinical presentation ranged from severe (onset in the first 3 months, usually with refractory epilepsy and early brain atrophy), to intermediate (onset in the first year with nystagmus and spasticity), and mild (onset around or after 12 months with minimal cognitive impairment and preserved independent walking). The most frequent RARS1 variant, c.5A>G, led to mild or intermediate phenotypes, whereas truncating variants and variants affecting amino acids close to the ArgRS active centre led to severe phenotypes. ArgRS activity was significantly reduced in three patients with intermediate and severe phenotypes; in a fourth patient with intermediate to severe presentation, we measured normal ArgRS activity, but found translation mainly of the short instead of the long ArgRS isoform.

Interpretation

Variants in RARS1 impair ArgRS activity and do not only lead to a classic hypomyelination presentation with nystagmus and spasticity, but to a wide spectrum, ranging from severe, early‐onset epileptic encephalopathy with brain atrophy to mild disease with relatively preserved myelination.
Roles of Postdiagnosis Accumulation of Morbidities and Lifestyle Changes in Excess Total and Cause‐Specific Mortality Risk in Rheumatoid Arthritis
Authors: Yoshida Kazuki , Lin Tzu‐Chieh , Wei Melissa Y. , Malspeis Susan , Chu Su H. , Camargo Carlos A. , Raby Benjamin A. , Choi Hyon K. , Tedeschi Sara K. , Barbhaiya Medha , Lu Bing , Costenbader Karen H. , Karlson Elizabeth W. , Sparks Jeffrey A.
Published: December 2019

Objective

To elucidate how postdiagnosis multimorbidity and lifestyle changes contribute to the excess mortality of rheumatoid arthritis (RA).

Methods

We performed a matched cohort study among women in the Nurses’ Health Study (1976–2018). We identified women with incident RA and matched each by age and year to 10 non‐RA comparators at the RA diagnosis index date. Specific causes of death were ascertained via death certificates and medical record review. Lifestyle and morbidity factors were reported biennially; 61 chronic conditions were combined into the Multimorbidity Weighted Index (MWI). After adjusting for baseline confounders, we used inverse probability weighting analysis to examine the mediating influence of postindex MWI scores and lifestyle factors on total, cardiovascular, and respiratory mortality, comparing women with RA to their matched comparators.

Results

We identified 1,007 patients with incident RA and matched them to 10,070 non‐RA comparators. After adjusting for preindex confounders, we found that hazard ratios (HRs) and 95% confidence intervals (95% CIs) were higher for total mortality (HR 1.46 [95% CI 1.32, 1.62]), as well as cardiovascular (HR 1.54 [95% CI 1.22, 1.94]) and respiratory (HR 2.75 [95% CI 2.05, 3.71]) mortality in patients with RA compared to non‐RA comparators. Adjusting for postindex lifestyle factors (physical activity, body mass index, diet, smoking) attenuated but did not substantially account for this excess RA mortality. After additional adjustment for postindex MWI scores, patients with RA had HRs of 1.18 (95% CI 1.05, 1.32) for total, 1.19 (95% CI 0.94, 1.51) for cardiovascular, and 1.93 (95% CI 1.42, 2.62) for respiratory mortality.

Conclusion

We found that MWI scores substantially accounted for the excess total and cardiovascular mortality among women with RA. This finding underscores the importance of monitoring for the total disease burden as a whole in monitoring patients with RA.
Adiposity and Physical Activity as Risk Factors for Developing Psoriatic Arthritis: Longitudinal Data From a Population‐Based Study in Norway
Authors: Thomsen Ruth S. , Nilsen Tom I. L. , Haugeberg Glenn , Gulati Agnete M. , Kavanaugh Arthur , Hoff Mari
Published: December 2019

Objective

Adiposity is prevalent among patients with psoriatic arthritis (PsA). However, the temporal relation is unclear. The present study was undertaken to investigate whether adiposity and body fat distribution are related to the risk of developing PsA, and whether physical activity could modify the possible risk.

Methods

We included 36,626 women and men from the Norwegian Nord‐Trøndelag Health Study without diagnosed PsA at baseline from 1995 to 1997. Cox regression analysis was used to estimate adjusted hazard ratios (HRs) with 95% confidence intervals (95% CIs) of incident PsA at follow‐up from 2006 to 2008.

Results

During follow‐up, 185 new cases of PsA were reported. Increases of 1 SD in body mass index (BMI) (4.2 and 3.5 kg/m2 for women and men, respectively) and waist circumference (10.8 and 8.6 cm, respectively) were associated with HRs of 1.40 (95% CI 1.24, 1.58) and 1.48 (95% CI 1.31, 1.68), respectively. Compared to individuals of normal weight, obese individuals had an HR of 2.46 (95% CI 1.65, 3.68), and overweight individuals had an HR of 1.41 (95% CI 1.00, 1.99). Comparing extreme quartiles of waist circumference yielded an HR of 2.63 (95% CI 1.73, 3.99). In analyses of combined effects using a BMI of <25 kg/m2 and high physical activity as reference, a BMI of ≥25 kg/m2 was associated with HRs of 2.06 (95% CI 1.18, 3.58) and 1.53 (95% CI 0.80, 2.91) among those with low and high physical activity levels, respectively. Corresponding HRs for high waist circumference and physical activity were 2.25 (95% CI 1.40, 1.63) and 1.85 (95% CI 0.95, 3.50).

Conclusion

The results suggest that adiposity, particularly central obesity, is associated with increased risk of incident PsA. Although there was no clear modifying effect of physical activity, high levels of physical activity reduced the risk of PsA, regardless of BMI.
Protein and Hydrophobic Association‐Regulated Hydrogels with Adhesive Adjustability in Different Materials
Authors: Xu Jianyu , Gao Guanghui , Duan Lijie , Sun Guoxing
Published: December 2019

Adhesiveness, as one of the basic properties of hydrogels, has attracted much attention in the fields of medical bandage, flexible wearable device, and electrolyte. However, the adhesive property is difficult to be adjusted on the surfaces of different substrates. Herein, casein, a model of protein, and a hydrophobic monomer (2‐methoxyethyl acrylate, MEA) are successfully introduced into polyacrylamide (pAAm) hydrogels. As a result, the pAAm–MEA–Casein hydrogels exhibited not only good mechanical property based on the multiple physical crosslinking, but also excellent adhesive adjustability for different hydrophobic and hydrophilic surfaces through the regulation of hydrophobic interactions. The tensile stress of pAAm–MEA10–Casein37.5 hydrogels can achieve 258 kPa with a strain of around 2200%. The adhesive performance is always kept after 40 times repeatedly bonding to the silicon rubber surface, and the interfacial toughness is around 115.22 J m−2. Moreover, the adjustable bonding of the hydrogel to the hydrophilic and hydrophobic materials can be achieved by changing the content of hydrophobic segments. This protein‐driven hydrophobic association strategy would open a new approach to design a new generation of adjustable adhesion soft materials for biomedical engineering.
Metasurfaces Composed of Plasmonic Molecules: Hybridization Between Parallel and Orthogonal Surface Lattice Resonances
Authors: Liu Shao‐Ding , Yue Peng , Zhang Shi , Wang Mingshan , Dai Hongwei , Chen Yiqin , Nie Zhong‐Quan , Cui Yanxia , Han Jun‐Bo , Duan Huigao
Published: December 2019

Multiple surface lattice resonances suppress radiative losses effectively around several spectral positions, thereby enhancing the light‐matter interactions and making them promising for multiwavelength related applications, and it is important to develop reliable methods to generate multiple lattice resonances. In analogy to natural materials composed of various kinds of molecules, this study proposed to construct metasurfaces with plasmonic artificial molecules, which represent distinct collective responses compared with that of single nanoparticles. It is shown that sharp multiple surface lattice resonances are excited due to the coupling between the localized resonances of plasmonic trimer molecules and the Rayleigh anomalies of the array, and there is a rarely observed parallel lattice resonance caused by the formation of equivalent dipoles perpendicular to the polarization. Particularly, even though the parallel mode is weak, a pronounced anticrossing behavior due to the hybridization with the orthogonal mode occurs when the resonance energies are approaching to each other, which results in two hybridized eigenmodes that possess both characteristics of parallel and orthogonal Rayleigh anomalies. Considering the excitation of the lattice resonances in asymmetric environments, the flexible tunability, and the ability to tailor the collective responses, metasurfaces constructed with artificial molecules are promising platforms to design ultrafast and compact photonic devices.
Impact of MYD88L265P mutation status on histological transformation of Waldenström Macroglobulinemia
Authors: Zanwar Saurabh , Abeykoon Jithma P. , Durot Eric , King Rebecca , Perez Burbano Gabriela E. , Kumar Shaji , Gertz Morie A. , Quinquenel Anne , Delmer Alain , Gonsalves Wilson , Cornillet‐Lefebvre Pascale , He Rong , Warsame Rahma , Buadi Francis K. , Novak Anne J. , Greipp Patricia T. , Inwards David , Habermann Thomas M. , Micallef Ivana , Go Ronald , Muchtar Eli , Kourelis Taxiarchis , Dispenzieri Angela , Lacy Martha Q. , Dingli David , Nowakowski Grzegorz , Thompson Carrie A. , Johnston Patrick , Thanarajasingam Gita , Bennani N. Nora , Witzig Thomas E. , Villasboas Jose , Leung Nelson , Lin Yi , Kyle Robert A. , Rajkumar S. Vincent , Ansell Stephen M. , Le‐Rademacher Jennifer G. , Kapoor Prashant
Published: December 2019

Histological transformation in Waldenström macroglobulinemia (WM) is an uncommon complication, with limited data, particularly regarding the impact of MYD88
L265P mutation on transformation. We examined risk factors and outcomes associated with transformation in WM, highlighting the role of MYD88
L265P mutation. Patients with WM seen at Mayo Clinic, Rochester, USA and University Hospital of Reims, France, between 01/01/1996 and December 31, 2017 were included; 50 (4.3%) of 1147 patients transformed to a high‐grade lymphoma, with median time‐to‐transformation of 4.5 (range 0‐21) years in the transformed cohort. The MYD88
L265P mutation status was known in 435/1147 (38%) patients (406 with non‐transformed WM and 29 patients in transformed cohort). On multivariate analysis, MYD88
WT status alone was an independent predictor of transformation (odds ratio, 7[95%CI: 2.1‐23]; P = .003). Additionally, the MYD88
WT status was independently associated with shorter time‐to‐transformation (HR 7.9 [95%CI: 2.3‐27; P = .001]), with a 5‐year transformation rate of 16% for MYD88
WT vs 2.8% with MYD88
L265P mutated patients. Patients with transformation demonstrated a significant increase in risk of death compared to patients who did not transform (HR 5.075; 95%CI: 3.8‐6.8; P < .001). In conclusion, the MYD88
WT status is an independent predictor of transformation and associated with a shorter time‐to‐transformation. Additionally, transformation conferred an inferior overall survival in patients with WM.
Morphology‐Reserved Synthesis of Discrete Nanosheets of CuO@SAPO‐34 and Pore Mouth Catalysis for One‐Pot Oxidation of Cyclohexane
Authors: Guo Xiangke , Xu Mengxia , She Minyi , Zhu Yan , Shi Taotao , Chen Zhaoxu , Peng Luming , Guo Xuefeng , Lin Ming , Ding Weiping
Published: December 2019

Discrete nanosheets of silicon‐doped AlPO4 molecular sieves (SAPO‐34) with a thickness of ≈7 nm have been prepared through morphology‐reserved synthesis with a lamellar aluminum phosphate as precursor. Cages of the nanosheets are in situ incorporated with copper oxide clusters. The CuO@SAPO‐34 nanosheets exhibit a large external surface area with a high number of (010) channel pores on the surface. Due to the thin morphology, copper oxide clusters occupy the outmost cages with a probability >50 %. The distinctive configuration facilitates a new concept of pore mouth catalysis, i.e., reactant molecules larger than the pores cannot enter the interior of the molecular sieves but can interact with the CuO clusters at “the mouth” of the pore. In heterogeneous catalysis, CuO@SAPO‐34 nanosheets have shown top performance in one‐pot oxidation of cyclohexane to adipic acid by O2, a key compound for the manufacture of nylon‐66, which is so far produced using non‐green nitric acid oxidation.
Suprakolloidale Selbstorganisation von bivalenten Janus‐3D‐DNA‐Origami über programmierbare, multivalente Wirt/Gast‐Wechselwirkungen
Authors: Loescher Sebastian , Walther Andreas
Published: December 2019

Wir stellen zweiwertige 3D‐DNA‐Origami‐Quader als monodisperse Kolloide vor und nutzen ihre Fähigkeit der molekularen Erkennung, um räumlich genau angeordnete Interaktionsmuster und eine definierte Anzahl supramolekularer Bindungsmotive zu erzeugen. Wir zeigen, dass Adamantan/β‐Cyclodextrin‐Wirt/Gast‐Einschlusskomplexe mit mäßiger Assoziationsstärke eine effiziente suprakolloidale Fibrillierung selbst bei hoher Verdünnung der 3D‐DNA‐Origami aufgrund kooperativer Multivalenz ermöglichen. Details der Assemblierung von Janus‐ und Nicht‐Janus‐3D‐DNA‐Origami zu suprakolloidalen Homo‐ und Heterofibrillen in Bezug auf Multivalenzeffekte, elektrostatische Abstoßung und Stöchiometrie werden aufgezeigt. Wir schlagen vor, dass die Vereinigung von 3D‐DNA‐Origami mit kolloidaler Selbstorganisation und supramolekularen Motiven neue Synergien an der Schnittstelle dieser Disziplinen bietet, um Multivalenzeffekte besser zu verstehen, strukturelle Komplexität zu fördern und die DNA‐Nanowissenschaften um Mechanismen zu erweitern, die Nicht‐DNA‐Assemblierung und Schaltung ergänzen.
Chiral N‐Heterocyclic Carbene Ligands Enable Asymmetric C−H Bond Functionalization
Authors: Thongpaen Jompol , Manguin Romane , Baslé Olivier
Published: December 2019

The asymmetric functionalization of C−H bond is a particularly valuable approach for the production of enantioenriched chiral organic compounds. Chiral N‐heterocyclic carbene (NHC) ligands have become ubiquitous in enantioselective transition‐metal catalysis. Conversely, the use of chiral NHC ligands in metal‐catalyzed asymmetric C−H bond functionalization is still at an early stage. This minireview highlights all the developments and the new advances in this rapidly evolving research area.
Kinetik und Mechanismus der mineralischen Atmung: Eisen‐Häme synchronisieren die Geschwindigkeit des Elektronentransfers
Authors: Chabert Valentin , Babel Lucille , Füeg Michael P. , Karamash Maksym , Madivoli Edwin S. , Herault Nelly , Dantas Joana M. , Salgueiro Carlos A. , Giese Bernd , Fromm Katharina M.
Published: December 2019

Anaerobe Mikroorganismen der Geobacter Gattung sind wichtige Elektronenquellen für die Synthese von Nanopartikeln, für die Biosanierung von verschmutztem Wasser und für Brennstoffzellen. Im Atmungsprozess dieser Spezies werden Elektronen von den Eisen‐Hämen der c‐Cytochrome aus der inneren Zellmembran zu den extrazellulären Metallionen geleitet, die an der äusseren Zellmembran gebunden sind. Die Elektronenproduktion und der Elektronenfluss erfolgten mit 5×105 e s−1 pro G. sulfurreducens. Die Mikroorganismen können die Geschwindigkeit des Elektronenflusses durch Erhöhung des Fe2+/Fe3+ Verhältnisses in den Multihäm‐Cytochromen erhöhen, wenn sich die Aktivität oder die Konzentration des extrazellulären Oxidationsmittels verringert. Dieser Mechanismus erlaubt es, dass die Atmung auch bei wechselnden Umweltbedingungen unverändert bleibt. Diese Homöostase ist eine notwendige Bedingung für lebende Systeme und macht G. sulfurreducens Mikroorganismen zu einer vielseitigen Elektronenquelle.
Highly Efficient Porous Carbon Electrocatalyst with Controllable N‐Species Content for Selective CO2 Reduction
Authors: Ye Lin , Ying Yiran , Sun Dengrong , Zhang Zhouyang , Fei Linfeng , Wen Zhenhai , Qiao Jinli , Huang Haitao
Published: December 2019

We report a straightforward strategy to design efficient N doped porous carbon (NPC) electrocatalyst that has a high concentration of easily accessible active sites for the CO2 reduction reaction (CO2RR). The NPC with large amounts of active N (pyridinic and graphitic N) and highly porous structure is prepared by using an oxygen‐rich metal–organic framework (Zn‐MOF‐74) precursor. The amount of active N species can be tuned by optimizing the calcination temperature and time. Owing to the large pore sizes, the active sites are well exposed to electrolyte for CO2RR. The NPC exhibits superior CO2RR activity with a small onset potential of −0.35 V and a high faradaic efficiency (FE) of 98.4 % towards CO at −0.55 V vs. RHE, one of the highest values among NPC‐based CO2RR electrocatalysts. This work advances an effective and facile way towards highly active and cost‐effective alternatives to noble‐metal CO2RR electrocatalysts for practical applications.
Nickel(0)‐Catalyzed Enantioselective [3+2] Annulation of Cyclopropenones and α,β‐Unsaturated Ketones/Imines
Authors: Bai Dachang , Yu Yanjiang , Guo Haiming , Chang Junbiao , Li Xingwei
Published: December 2019

Ni0‐catalyzed chemo‐ and enantioselective [3+2] cycloaddition of cyclopropenones and α,β‐unsaturated ketones/imines is described. This reaction integrates C−C bond cleavage of cyclopropenones and enantioselective functionalization by carbonyl/imine group, offering a mild approach to γ‐alkenyl butenolides and lactams in excellent enantioselectivity (88–98 % ee) through intermolecular C−C activation.
Nanoporous phenanthroline polymer locked Pd as highly efficient catalyst for Suzuki‐Miyaura Coupling reaction at room temperature
Authors: Chen Jian , Zhang Ju , Zhang Yan , Xie Mingjiang , Li Tao
Published: December 2019

Because of the intrinsic advantages, Suzuki coupling reactions have been one of the most popular coupling reactions in organic synthesis, however developing a high‐performance heterogeneous catalyst for Suzuki coupling reactions in aqueous media at low temperature (e.g. room temperature) is still a challenge. Herein, a heterogeneous catalyst with coordinated Pd as active site and a designed conjugated phenanthroline based porous polymer (CPP) as support was fabricated. Systematically investigation on CPP support by Fourier transform infrared spectroscopy (FT‐IR), Thermogravimetric analysis (TGA), Transmission electron microscopy (TEM), N2 adsorption–desorption isotherm and Scanning electron microscopy (SEM) show that the derived CPP catalyst support owns a porous structure, moderately good surface area (141 m2/g) and an excellent thermal stability. As a heterogeneous catalyst for the synthesis of biphenyl derivatives via Suzuki coupling, Pd/CPP achieves an excellent catalytic performance and recycling ability towards Suzuki reaction of various reactants at room temperature in ethanol‐water medium.