Multivalent Sulfur Vacancy-Rich NiCo2 S4 @MnO2 Urchin-Like Heterostructures for Ambient Electrochemical N2 Reduction to NH3.

Innovative advances in the exploitation of effective electrocatalytic materials for the reduction of nitrogen (N2 ) to ammonia (NH3 ) are highly required for the sustainable production of fertilizers and zero-carbon emission fuel. In order to achieve zero-carbon footprints and renewable NH3 production, electrochemical N2 reduction reaction (NRR) provides a favorable energy-saving alternative but it requires more active, efficient, and selective catalysts. In current work, sulfur vacancy (Sv)-rich NiCo2 S4 @MnO2 heterostructures are efficaciously fabricated via a facile hydrothermal approach followed by heat treatment. The urchin-like Sv-NiCo2 S4 @MnO2 heterostructures serve as cathodes, which demonstrate an optimal NH3 yield of 57.31 µg h-1  mgcat -1 and Faradaic efficiency of 20.55% at -0.2 V versus reversible hydrogen electrode (RHE) in basic electrolyte owing to the synergistic interactions between Sv-NiCo2 S4 and MnO2 . Density functional theory (DFT) simulation further verifies that Co-sites of urchin-like Sv-NiCo2 S4 @MnO2 heterostructures are beneficial to lowering the energy threshold for N2 adsorption and successive protonation. Distinctive micro/nano-architectures exhibit high NRR electrocatalytic activities that might motivate researchers to explore and concentrate on the development of heterostructures for ambient electrocatalytic NH3 generation.

Pakistani Student Nurses' perceptions of their hospital's health professionals' attitudes and suggested ways to improve patient care - An untainted view.

BACKGROUND & OBJECTIVES: Feedback brings a fresh perspective and improvement in any organization. Health professionals (HPs) lose insight of the gaps in medical care. The views of student nurses can help improve systems. The objective of this study was to assess the views of our student nurses and how they perceive the way the doctors and HPs work in our hospital and comment on training, attitudes, care pathways, teamwork, and what needed to be improved. METHODS: A proforma based qualitative study was carried out at the Nurses' Training Centre of PAF Hospital and Fazaia Medical College, Islamabad, from January to March 2020. After approval, a semi-structured proforma with open and closed ended questions was administered, in English and Urdu. The results were analyzed by comparative numbers and percentages for each question and descriptive responses were grouped in recurring themes and analyzed for content and their constructive value. RESULTS: Out of 85 nursing cadets, the proforma could be administered to 61(M=38(62.3%) and F=23(37.7%). Most were FSc with 26% graduates. Majority of the female students' main reason for joining was to serve humanity, unlike most males. According to gender many responses were interestingly different. Majority of females thought male doctors were better (86%). Only 36% said the doctors were sincere in care of patients. Most thought that we needed to improve patient counseling. Most thought the seniors treated them unfairly, but bullying was negligible. They wanted the senior HPs to improve their attitudes and ensure adequate equipment in the wards. They were worried about personal security from patients and relatives. Dedicated mental health services to deal with stress of witnessing every day misery and death was suggested. CONCLUSIONS: Doctors need to improve their counseling skills and should talk more to the patients and their relatives. They should acknowledge the nursing students and improve teamwork. Belittling them in front of others harms their self-efficacy. Simple corrections like punctuality, ownership of their patients and improvement of equipment and systems can improve patient care.

Layered Double Hydroxide (MgFeAl-LDH)-Based Polypropylene (PP) Nanocomposite: Mechanical Properties and Thermal Degradation.

This work analyzes the thermal degradation and mechanical properties of iron (Fe)-containing MgAl layered double hydroxide (LDH)-based polypropylene (PP) nanocomposite. Ternary metal (MgFeAl) LDHs were prepared using the urea hydrolysis method, and Fe was used in two different concentrations (5 and 10 mol%). Nanocomposites containing MgFeAl-LDH and PP were prepared using the melt mixing method by a small-scale compounder. Three different loadings of LDHs were used in PP (2.5, 5, and 7.5 wt%). Rheological properties were determined by rheometer, and flammability was studied using the limiting oxygen index (LOI) and UL94 (V and HB). Color parameters (L*, a*, b*) and opacity of PP nanocomposites were measured with a spectrophotometer. Mechanical properties were analyzed with a universal testing machine (UTM) and Charpy impact test. The thermal behavior of MgFeAl-LDH/PP nanocomposites was studied using differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA). The morphology of LDH/PP nanocomposites was analyzed with a scanning electron microscope (SEM). A decrease in melt viscosity and increase in burning rate were observed in the case of iron (Fe)-based PP nanocomposites. A decrease in mechanical properties interpreted as increased catalytic degradation was also observed in iron (Fe)-containing PP nanocomposites. Such types of LDH/PP nanocomposites can be useful where faster degradation or faster recycling of polymer nanocomposites is required because of environmental issues.

The Pattern of Superficial Lymphadenopathy on Fine Needle Aspiration Cytology in Clinical Practice in Islamabad.

BACKGROUND:  In adults, lymph nodes are not normally palpable. A number of patients with asymptomatic lymphadenopathy never visit physicians for the condition, and thus, this important sign is often missed by the medical practitioner if it is not the presenting complaint. The incidence of lymphadenopathy is suggested to be increasing. While lymphadenopathy is benign and self-limiting in most patients, the underlying disease may range from treatable infectious etiology to malignant neoplasms. In most cases clinical examination and history guide towards the cause of lymphadenopathy. In recent years, fine needle aspiration cytology (FNAC) has become an easy clinical tool (with or without the assistance of CT, MRI, and ultrasound) for the diagnosis of the underlying cause of lymphadenopathy. AIMS AND OBJECTIVES:  To find out the cytomorphological pattern in superficial lymphadenopathy with the help of FNAC. MATERIALS AND METHODS:  This descriptive cross-sectional study was conducted at HBS General Hospital, Islamabad from January 2017 to June 2019. Patients presenting with superficial lymphadenopathy were included in the study. FNAC was performed by the pathologist, histopathological reports were examined and analyzed using Statistical Package for the Social Sciences (SPSS) version 22 (IBM Corp., Armonk, NY).  Results: Six hundred and thirty-two patients underwent FNAC. Tuberculous lymphadenitis was the most common diagnosis (56.1%) followed by reactive hyperplasia (28.29%). The sample showed metastatic malignancy 3.36% and lymphoma 2.05%. Cervical lymphadenopathy was the most common site for TB (49.36%). Metastatic cancer observed in cervical lymph nodes was 3.16% and lymphoma was 1.74%. CONCLUSION:  FNAC is recognized as a simple and safe diagnostic technique that can diagnose cases of superficial and deep lymphadenopathy easily. The most common cause of superficial lymphadenopathy in our study was tuberculosis with cervical lymph nodes.

Preparation of Photoactive Transition-Metal Layered Double Hydroxides (LDH) to Replace Dye-Sensitized Materials in Solar Cells.

This work highlights the use of Fe-modified MgAl-layered double hydroxides (LDHs) to replace dye and semiconductor complexes in dye-sensitized solar cells (DSSCs), forming a layered double hydroxide solar cell (LDHSC). For this purpose, a MgAl-LDH and a Fe-modified MgAl LDH were prepared. X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) spectroscopy were used to analyze the structural properties, morphology, and success of the Fe-modification of the synthesized LDHs. Ultraviolet-visible (UV-Vis) absorption spectroscopy was used to analyze the photoactive behavior of these LDHs and compare it to that of TiO2 and dye-sensitized TiO2. Current-voltage (I-V) solar simulation was used to determine the fill factor (FF), open circuit voltage (VOC), short circuit current (ISC), and efficiency of the LDHSCs. It was shown that the MgFeAl-LDH can act as a simultaneous photoabsorber and charge separator, effectively replacing the dye and semiconductor complex in DSSCs and yielding an efficiency of 1.56%.

Synthesis and characterization of MgAl-DBS LDH/PLA composite by sonication-assisted masterbatch (SAM) melt mixing method.

This research work is based on the comparison of the mixing phenomena of magnesium-aluminum (MgAl) layered double hydroxides (LDHs) intercalated by dodecylbenzene sulfonate (MgAl-DBS) in poly(lactic acid) (PLA). Two mixing techniques were used to compare the dispersion of LDHs in PLA such as sonication-assisted masterbatch (SAM) melt mixing and direct melting (DM) methods. MgAl LDHs synthesized by the urea hydrolysis method and intercalated with DBS anions using anion exchange reaction and were used in different ratios in PLA (1.25, 2.5, and 5 wt%). MgAl LDHs and their anion intercalation were studied by the X-ray diffraction analysis (XRD) method. Different properties of LDH/PLA composites were compared to analyze the effect of these mixing techniques. Dispersion and exfoliation of LDHs in PLA were investigated by X-ray diffraction analysis (XRD) and transmission electron microscopy (TEM). Influences on the rheological properties were evaluated by analyzing the complex viscosities (η*), storage modulus (G') and loss modulus (G'') by using a rheometer. The thermal properties, thermal stability and effect on crystallinity of composites made with the two mixing techniques were analyzed by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) respectively. The mixing mechanism and amount of MgAl-DBS LDHs have a notable effect on the properties of PLA composites with sonication-assisted masterbatch melt mixing techniques giving better dispersion of LDHs in PLA composites as compared to direct melt mixing.

Comparison of transition metal (Fe, Co, Ni, Cu, and Zn) containing tri-metal layered double hydroxides (LDHs) prepared by urea hydrolysis.

This paper details a successful synthesis and comparison of a range of tri-metal hydrotalcite-like layered double hydroxides (LDHs) using urea hydrolysis. Transition-metal-substituted MgMAl-LDHs were synthesized with M = Fe, Co, Ni, Cu or Zn. 5 mol% and 10 mol% substitutions were performed, where Mg was substituted with Co, Ni, Cu and Zn, and Al with Fe. The successful synthesis of crystalline MgMAl-LDHs was confirmed using X-ray powder diffraction (XRD) analysis. Energy-dispersive X-ray (EDX) spectroscopy was used to identify substituted metals and determine changes in composition. Changes in morphology were studied using scanning electron microscopy (SEM). Thermogravimetric analysis was used to determine the effect of Fe-, Co-, Ni-, Cu- or Zn-substitution on the thermal degradation of the MgMAl-LDH phase. The structure, morphology and thermal behavior of the LDHs were shown to be influenced by the substituted transition metals. The observed thermal stability took the order MgNiAl- > MgFeAl- = MgAl- ≥ MgCoAl- > MgCuAl- > MgZnAl-LDH. The urea hydrolysis method was shown to be a simple preparation method for well-defined crystallite structures with large hexagonal platelets and good distribution of transition metal atoms in the substituted LDHs.

Comparison of nano-structured transition metal modified tri-metal MgMAl-LDHs (M = Fe, Zn, Cu, Ni, Co) prepared using co-precipitation.

Comparison of layered double hydroxides (LDHs) synthesised using different methods, conditions and post-treatment is difficult to achieve because these greatly modify their material properties. This paper aims to provide a comparison of material properties for modified quintinite, where all LDHs were synthesised at the same conditions - thus allowing for direct comparison of the material properties obtained. Nano-structured materials were formed in all cases. The nano-structured transition metal (TM) MgMAl-LDHs were synthesised using constant pH co-precipitation. Five TMs (M = Fe, Co, Ni, Cu, Zn) were included in the LDH layers with molar substitutions of 0.5%, 1%, 5%, 10%, and 25% based on Mg-replacement for divalent TM cations and Al-replacement for trivalent TM cations. The materials were characterised using powder X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), scanning electron microscopy (SEM), attenuated total reflectance Fourier transform infrared analysis (ATR-FTIR), thermogravimetric analysis (TGA) and particle size analysis (PSA). The modified LDHs were synthesised free of major by-products and with similar morphologies. It could be shown that the crystallite dimensions varied between the different TM substitutions, that morphological changes were visible for some of the TMs used, that the processability depended on the TMs substituted, and that the substitution of TMs influenced the thermal stability of the LDHs.

Different transition metal combinations of LDH systems and their organic modifications as UV protecting materials for polypropylene (PP).

In this research, the use of layered double hydroxides (LDHs) as ultraviolet (UV) light-protecting additives for PP is explored. Different LDHs, such as ZnTi, ZnSn, ZnGa, ZnCr and CdCr LDHs, were prepared and their UV absorptions were characterized. The ZnTi LDHs showed higher UV absorption than the other four metallic combinations and were further organically modified with dodecylbenzene sodium sulfonate (SDBS) and lauric acid (LA). Nanocomposites of polypropylene (PP) with four different types of LDHs, ZnTi, ZnSn, ZnTi-SDBS and ZnTi-LA, were prepared at concentrations of 5%. The crystallinities and layered structures of all the metallic combinations of LDHs were characterized by wide angle X-ray spectroscopy (WAXS) and ultraviolet visible (UV-vis) absorption spectroscopy, and their crystal morphologies were studied by scanning electron microscopy (SEM). The decomposition and thermal properties of the nanocomposites and pure PP were analyzed by thermogravimetric analysis (TGA) and transmission electron microscopy (TEM) and by their photo-oxidation behavior. The addition of these organically modified and unmodified LDHs showed significant changes in the thermal decomposition of PP. The thermal stability of PP was increased to around 70 °C by the addition of SDBS-modified ZnTi LDHs (5% by weight), and an increase in induction time of about 300% was determined.