Catalytic reduction of nitroarenes by palladium nanoparticles decorated silica@poly(chitosan-N-isopropylacrylamide-methacrylic acid) hybrid microgels.

Conversion of toxic nitroarenes into less toxic aryl amines, which are the most suitable precursors for different types of compounds, is done with various materials which are costly or take more time for this conversion. In this regards, a silica@poly(chitosan-N-isopropylacrylamide-methacrylic acid) Si@P(CS-NIPAM-MAA) Si@P(CNM) core-shell microgel system was synthesized through free radical precipitation polymerization (FRPP) and then fabricated with palladium nanoparticles (Pd NPs) by in situ-reduction method to form Si@Pd-P(CNM) and characterized with XRD, TEM, FTIR, SEM, and EDX. The catalytic efficiency of Si@Pd-P(CNM) hybrid microgels was studied for reduction of 4-nitroaniline (4NiA) under diverse conditions. Different nitroarenes were successfully transformed into their corresponding aryl amines with high yields using the Si@Pd-P(CNM) system as catalyst and NaBH4 as reductant. The Si@Pd-P(CNM) catalyst exhibited remarkable catalytic efficiency and recyclability as well as maintaining its catalytic effectiveness over multiple cycles.

Silica@poly(chitosan-N-isopropylacrylamide-methacrylic acid) microgels: Extraction of palladium (II) ions and in situ formation of palladium nanoparticles for pollutant reduction.

Most of the transition metal ions and organic dyes are toxic in nature. Therefore, their removal from water is imperative for human health. For this purpose, various types of systems have been developed to tackle either transition metal ions or organic dyes individually. A core-shell microgel system is introduced which is capable of effectively removing both types (toxic organic dyes and transition metal ions) of pollutants. A long-rod-shaped silica@poly(chitosan-N-isopropylacrylamide-methacrylic acid) S@P(CS-NIPAM-MAA) S@P(CNM) core-shell microgel system was developed by free radical precipitation polymerization method (FRPPM). S@P(CNM) was utilized as an adsorbent for extracting palladium (II) (Pd (II)) ions from water under different concentrations of S@P(CNM), several agitation times, palladium (II) ion content, and pH levels. The adsorption data of Pd (II) ions on S@P(CNM) was evaluated by various adsorption isotherms. The kinetic study was investigated by employing pseudo-2nd order (Ps2O), Elovich model (ElM), intra-particle diffusion (IPDM), and pseudo-1st order (Ps1O). Additionally, palladium nanoparticles (Pd NPs) were generated via in-situ reduction of adsorbed Pd (II) ions within the P(CNM) shell region of S@P(CNM). The resulting Pd NPs loaded S@P(CNM) exhibited the capability to reduce organic pollutants like methyl orange (MeO), 4-nitrophenol (4NiP), methylene blue (MeB), and Rhodamine B (RhB) from aqueous medium. 0.766 min-1, 0.433 min-1, 0.682 min-1, and 1.140 min-1 were the values of pseudo 1st order rate constant (kobs) for catalytic reduction of MeB, 4NiP, MeO, and RhB respectively. The S@Pd-P(CNM) system exhibits significant catalytic potential for various organic transformations.

Is a Preservation Solution for Living Donor Liver Transplantation Needed? Adding a New Chapter in LDLT!

Preservation solutions are required for organ viability in deceased donor liver transplantation (LT). However, their role in live donor LT (LDLT) has not been standardized. Methods: Eighty adult recipients who underwent right lobe LDLT at the Department of Liver Transplantation Surgery, Gambat, Pakistan, were studied. Based on shorter cold ischemia time and no back table reconstruction work, recipients were assigned to receive "no preservation solution" (cases/non-histidine-tryptophan-ketoglutarate group; n = 40) or "HTK group" (controls; n = 40). Early allograft dysfunction (bilirubin, transaminases, and international normalized ratio), postoperative complications (biliary and vascular), hospital stay, and 1-y survival were reported. The direct cost was also reported. Results: Demographics and clinical characteristics were comparable in the 2 groups. Comparing cases versus controls, mean bilirubin, alanine aminotransferase, aspartate aminotransferase, and international normalized ratio on postoperative day 7 were similar in the 2 groups. Five (12.5%) cases and 4 (10%) controls developed early allograft dysfunction (P = 0.72). Post-LT complications (biliary leak 2.5% in cases versus 0 in control), strictures (15% in cases versus 17.5% in controls), hepatic artery thrombosis (2.5% versus 00%)' and portal vein thrombosis (0 versus 2.5%) were comparable. Mean hospital stay (10.80 + 2.36 and 11.78 + 2.91 d) and 30 d mortality (2.5% versus 5%) were also comparable. Finally, 1-y survival based on Kaplan-Meier analysis was comparable in both groups (ie, 92.5%; non-HTK group versus 90%; HTK group) (P = 0.71). The direct cost of using a non-HTK-based approach was less than the HTK solution. Conclusion: In a selected cohort of right lobe LDLT recipients, preservation solutions can be avoided safely with comparable outcomes.

A Low-Cost Metamaterial Sensor Based on DS-CSRR for Material Characterization Applications.

This paper presents a metamaterial sensor using a double slit complementary square ring resonator (DS-CSRR) that has been utilized for the measurement of dielectric materials, especially coal powder. The design is optimized for best performance of deep notch depth in transmission coefficient (Magnitude of S21). Sensitivity analysis of transmission coefficient with respect to structure dimensions has been carried out. Metamaterial properties of double negative permitivity and permeability were extracted from the S-parameters of this sensor. The optimized structure is fabricated using low cost FR-4 PCB board. Measured result shows resonance frequency of 4.75 GHz with a deep notch up to -41 dB. Simulated and measured results show good agreement in desired frequency band. For material characterization, first, two known materials are characterized using this metamaterial sensor. Their respective resonances and dielectric constants are known, so the transcendental equation of the sensor is formulated. Afterwards, the proposed sensor is used for dielectric measurement of two types of coal powder, i.e., Anthracite and Bituminous. The measured value of dielectric constant of Anthracite coal is 3.5 and of Bituminous coal is 2.52. This is a simple and effective nondestructive measurement technique for material testing applications.

Safety of glucose-6 phosphate dehydrogenase deficient donors in living right lobe liver donation.

BACKGROUND: The literature lacks data on World Health Organization (WHO) class II and III deficient liver donors who underwent right hepatectomy during living donor liver transplantation (LDLT). METHODS: In this prospective cohort study, we compared the perioperative outcomes of 15 glucose-6 phosphate dehydrogenase (G6PD) deficient living liver donors with a matched cohort of 39 nondeficient living liver donors undergoing right lobe donation. RESULTS: Out of 15 G6PD deficient donors, four (26.67%) donors had class II, and 11 (73.34%) had class III G6PD deficiency. The mean postoperative trough hemoglobin level was significantly lower in the deficient group than the nondeficient group (9.38 ± 1.59 g/dL vs. 10.27 ± .91 g/dL, p = .046). The mean peak indirect bilirubin level was significantly higher in the deficient group than the nondeficient group (2.22 ± 1.38 mg/dL vs. 1.40 ± .89 mg/dL, p = .047), and a similar trend was observed in total serum bilirubin (3.99 ± 2.57 mg/dL vs. 2.99 ± 1.46 mg/dL, p = .038). Biochemical evidence of hemolysis was found only in three (20%) deficient donors, but none of them needed a blood transfusion. No mortality was observed in either group. All other parameters, including demographics, operative parameters, graft characteristics, and hospital stay were comparable between both groups (p > .05). CONCLUSION: G6PD deficiency with WHO class II and above should not be considered a contraindication for right lobe donation.

Challenges of Pediatric Anesthesia Services and Training Infrastructure in Tertiary Care Teaching Institutions in Pakistan: A Perspective From the Province of Sindh.

BACKGROUND: Pakistan is a lower middle-income country located in South Asia with a population of nearly 208 million. Sindh is its second largest province. The aim of this survey was to identify the current setup of pediatric services, staffing, equipment, and training infrastructure in the teaching hospitals of Sindh. METHODS: The survey was conducted between June 2018 and September 2018. A questionnaire was designed with input from experts and pretested. One faculty coordinator from each of 12 of the 13 teaching hospitals (7 government and 5 private) completed the form. Information was exported into Statistical Package for the Social Sciences (SPSS) version 22. Frequency and percentages were computed for all variables. Confidentiality was ensured by anonymizing the data. RESULTS: Anesthesia services are provided by consultants with either membership or fellowship in anesthesia of the College of Physicians and Surgeons of Pakistan (CPSP). All drugs on the World Health Organization (WHO) essential medication list were available, although narcotic supply was often inconsistent. Weak areas identified were absence of standardization of practice regarding premedication, preoperative laboratory testing, pain assessment, and management. No national practice guidelines exist. Pulse oximeters and capnometers were available in all private hospitals but in only 86% and 44% of the government hospitals, respectively. Some training centers were not providing the training as outlined by the CPSP criteria. CONCLUSIONS: Several gaps have been identified in the practice and training infrastructure of pediatric anesthesia. There is a need for national guidelines, standardization of protocols, provision of basic equipment, and improved supervision of trainees. One suggestion is to have combined residency programs between private and government hospitals to take advantage of the strengths of both. Recommendations by this group have been shared with all teaching hospitals and training bodies.

Challenges of continuation of live liver donor programme during COVID-19 pandemic in Pakistan: outcomes and lessons learned.

BACKGROUND: COVID-19 pandemic has globally affected healthcare including the transplantation programmes. MATERIALS AND METHODS: We retrospectively studied the impact of COVID-19 on live liver donor (LLD) programme at liver transplant centre in Gambat, Pakistan. Standard operative procedures (SOPs) including COVID-19 nasopharyngeal swab PCR, CT scans, personal protective equipment use, 6-feet distancing were developed for LLD and transplant team to mitigate COVID-19 exposure. We compared the complications, healthcare utilisation (hospital stay, readmission) and mortality between two LLD cohorts-before and during COVID-19 pandemic from March 2019 to December 2020. RESULTS: During study period 300 LLD surgeries were performed. There was an increase in rate of LLDs from 132 (44%) in pre-COVID to 168 (56%) during COVID-19 era. Average numbers of transplants per month performed during pre-COVID and during COVID-19 era were 10.1 and 14, respectively. No donor has developed COVID-19 infection during hospitalisation. Rate of all LLD complications (32 (21.47%) and 49 (29.16%), p=0.43), uneventful discharges (120/168 (71.4%) and 88/132 (66.6%), p<0.05), mean hospital stay (6±2 days and 5±2 days, p=0.17) and readmission (5 (4%) and 3 (1.8%), p=0.43) were similar during the pre-COVID and COVID-19 era. No donor mortality was observed during study period. CONCLUSION: With the implementation of mindful SOPs, rate of LLD increased without any case of COVID-19 infection. Our SOPs were helpful in continuation of LLD programme in a developing country during COVID-19 pandemic.

Synthesis of a 2D copper(II)-carboxylate framework having ultrafast adsorption of organic dyes.

Two-dimensional (2D) coordination polymers are very interesting materials for their attractive applications. A novel 2D metal-organic framework (MOF) was derived from copper(II) and amino benzoic acid under both room temperature and solvothermal reaction conditions using different solvents. From both of the synthesis methods, an identical MOF was crystalized with monoclinic crystal system having P21/c space group. Hirshfeld surface analysis is carried out to explore the non-covalent interactions obtained from single crystal XRD investigation in terms of percentage contribution of each interatomic contact involved in packing of molecules into MOF structure. The microstructure analysis and surface morphology studies revealed the 2D layered regular pattern of rhombus disks of ~5 µm thickness throng together via clustering of these rhombic shaped flakes as flowers (ranging 50-100 µm in size) having uniform elemental composition. This 2D MOF efficiently adsorbed organic dyes (methylene blue, methyl orange, and methyl red) from their aqueous solutions. The 2D copper-carboxylate framework (1.2 g/L) exhibited high adsorption rates for organic dyes (0.15-0.19 mM), and >90% of these dyes could be captured as soon as they are exposed to MOF suspension (1 min) in each case. The dye removal efficiency is credited to synergy among structure, ionic strength, shapes and dimensions of dyes with respect to MOF structure. The microstructure of MOF along with electronic interactions like electrostatic, hydrogen bonding, π-π interactions and coordination to open metal sites, might contribute to the ultrafast dye adsorption process by MOF. The adsorption phenomenon is spontaneous and followed the pseudo-second order kinetic mechanism. DFT calculations revealed important electronic parameters of the dyes and model MOF systems, and novel insights with respect to possible dye-MOF interactions. The MOF remained quite stable during the dye adsorption and was regenerated easily for the successful subsequent use.

Synthesis of Heart/Dumbbell-Like CuO Functional Nanostructures for the Development of Uric Acid Biosensor.

It is always demanded to prepare a nanostructured material with prominent functional properties for the development of a new generation of devices. This study is focused on the synthesis of heart/dumbbell-like CuO nanostructures using a low-temperature aqueous chemical growth method with vitamin B12 as a soft template and growth directing agent. CuO nanostructures are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) techniques. CuO nanostructures are heart/dumbbell like in shape, exhibit high crystalline quality as demonstrated by XRD, and have no impurity as confirmed by XPS. Apparently, CuO material seems to be porous in structure, which can easily carry large amount of enzyme molecules, thus enhanced performance is shown for the determination of uric acid. The working linear range of the biosensor is 0.001 mM to 10 mM with a detection limit of 0.0005 mM and a sensitivity of 61.88 mV/decade. The presented uric acid biosensor is highly stable, repeatable, and reproducible. The analytical practicality of the proposed uric acid biosensor is also monitored. The fabrication methodology is inexpensive, simple, and scalable, which ensures the capitalization of the developed uric acid biosensor for commercialization. Also, CuO material can be used for various applications such as solar cells, lithium ion batteries, and supercapacitors.

Effect of Organophasphate poisoning among patients reporting at a tertiary healthcare facility of Sindh Pakistan.

OBJECTIVE: To determine the effect of organophosphate poisoning (OPP) among patients at tertiary healthcare, Pakistan. METHODS: This cohort study was conducted over a six-year period (January 2011 to December 2016) of OPP patients admitted to the intensive care unit of Peoples University of Medical & Health Sciences for Women SBA, Hospital Pakistan and their outcome was determined. RESULTS: Total mortality was 17.39% (84 deaths in 483 patients, excluding those referred to Karachi). Out of these 84 deaths, 65 patients (13.46%) expired due to cardiorespiratory failure, 17 deaths (3.52%) followed due to complication of mechanical ventilation & ICU acquired infection and two deaths (0.41%) occurred due to renal failure. The major cause of poisoning was deliberate self-harm /suicidal intention (93.02%), with gender distribution of female (57.07%) and male (35.95%), followed by unintentional/accidental exposure (6.98%) in males. The intensive supportive treatment, precise and appropriate respiratory care, and adequate amount of atropine and pralidoxime doses are keys to reducing the OPP patient's mortality. CONCLUSION: Organophosphate poisoning (OPP) intoxication is common in female gender. The easy availability of these harmful compounds has resulted in increased mortality either by accidental exposure or most often by the deliberate suicidal attempt.

Why more research needs to be done on echinococcosis in Pakistan.

BACKGROUND: Echinococcosis has a worldwide geographical distribution with endemic foci on every inhabited continent. Due to the frequent outbreaks in different parts of Pakistan in the recent past, echinococcosis is being described as a neglected tropical disease and is considered one of the most neglected parasitic diseases in the country. In endemic regions, predominantly settings with limited resources, there are high numbers of echinococcosis patients, as these communities do not have access to appropriate treatment. In Pakistan, there are limited reports on echinococcosis. The disease is prevalent in human and livestock, but this has not been sufficiently explored yet. Pakistan is an agricultural country and due to the disease's zoonotic mode of transmission, there is a dire need of future research on it. The present paper is an effort to highlight the importance of echinococcosis in Pakistan. DISCUSSION: There is a dire need for future research on echinococcosis in Pakistan as very few investigations had been carried out on this topic thus far. The prevalence of the disease in neighbouring countries highlights that Pakistan might be at severe risk of this zoonotic infection and further supports the need for more research. In Pakistan, the majority of the population lives in rural areas with limited acess to proper hygienic/sanitary facilities. These conditions favour the outbreak of diseases such as echinococcosis. The limited available data could result in higher outbreaks in the future, and thus cause the already weak healthcare system to overburden. The country has a meagre annual budget for health, which is being spent on known infections such as polio, dengue fever and hepatic viral infections. A proper surveillance system for echinococcosis is required across the country as treatment is usually expensive, complicated and may require extensive surgery and/or prolonged drug therapy. Development of new/novel drugs and other treatment modalities receives very little, if any, attention. Prognostic awareness programmes against this infection involve deworming of the infected animals, improved food inspection and slaughterhouse hygiene, and public education campaigns. CONCLUSION: Future research on echinococcosis is anticipated to demonstrate whether the epidemiology, diagnosis and recombinant vaccines/antibodies relating to echinococcosis can meet the quality standards (purity, potency, safety and efficacy) defined by the World Health Organization. Research work should be carried out on the epidemiology and serodiagnosis of echinocossis in the different areas of Pakistan, which will be useful for the proper eradication of echinococcosis in this region. The health department should implement awareness-raising campaigns for the general public in order to reduce the burden of disease.

Effect of Electron-Beam Irradiation on Organic Semiconductor and Its Application for Transistor-Based Dosimeters.

The effects of electron-beam irradiation on the organic semiconductor rubrene and its application as a dosimeter was investigated. Through the measurements of photoluminescence and the ultraviolet photoelectron spectroscopy, we found that electron-beam irradiation induces n-doping of rubrene. Additionally, we fabricated rubrene thin-film transistors with pristine and irradiated rubrene, and discovered that the decrease in transistor properties originated from the irradiation of rubrene and that the threshold voltages are shifted to the opposite directions as the irradiated layers. Finally, a highly sensitive and air-stable electron dosimeter was fabricated based on a rubrene transistor.

Risk mapping of bovine hypodermosis using geographical information system (GIS) in cattle of subtropical region, Pakistan.

INTRODUCTION: Hypodermosis is an ectoparasitic disease of cattle caused by Hypoderma lineatum and Hypoderma bovis. It is an important health problem of cattle, leading to considerable economic losses. There are various factors that are involved in the spread of this disease such as herd size, location, temperature, humidity, and precipitation. METHODOLOGY: Blood samples from 112 herds were collected to determine the presence of Hypoderma spp. infestation. For these herds, size and location were determined; temperature, humidity, and precipitation data were obtained from meteorological stations; and topographic features were obtained from existing maps and through field work. A regression analysis was then used to generate a risk factor analysis profile for hypodermosis and geographic information system (GIS) was used to map the risks. RESULTS: The GIS map developed showed the degree of infestation in different geographical locations at district and village levels. Cluster analysis demonstrated that hypodermosis prevalence varied within zones and across zones. The regression analysis showed that the temperature in the months of January, February, March, August, and November, and the precipitation in September and October had significant results (p < 0.05) when all the risks factors were analyzed. CONCLUSIONS: It is concluded that different ecological factors have an important impact on the intensity and infestation rate of hypodermosis across the globe. The present study might be used to control and eradicate the hypodermosis across the globe.

MOLECULAR CONFIRMATION OF ENTEROVIRUS FROM SEWAGE AND DRINKING WATER SAMPLES FROM THREE CITIES, PAKISTAN: A POTENTIAL RISK FACTOR FOR PUBLIC HEALTH.

Gastroenteritis causes from 4 to 10 million children deaths every year worldwide, mainly from infection with water-borne Enteroviruses, which consist of 67 diverse serogroups. Forty-two sewage and drinking water samples from three metropolitan cities of Pakistan were analyzed for the occurrence of Enterovirus by nested RT-PCR amplification. Molecular detection was based on amplification of a part of 5'UTR region of the viruses. Our results revealed an alarming situ- ation in densely populated areas of the three main cities of Pakistan: 28%, 19% and 21% of drinking water samples were positive for enteroviruses in Islamabad, Rawalpindi and Lahore, respectively. Sequence analysis and phylogenetic study of the amplified region of the virus revealed its close relationship with Coxsackie A strains reported from Greece, Singapore and USA.

Angle dependent focal spot size of a conical X-ray target.

Misaligned phantoms may severely affect the focal spot calculations. A method is proposed to determine the geometry of the X-ray target and the position of the image radiograph around the X-ray target to get a relatively smaller focal spot size. Results reveal that the focal spot size is not always isotropic around the target but it decreases as the point of observation shifts radially away from the center line of the conical X-ray target. This research will help in producing high quality X-ray images in multi-directions by properly aligning the phantoms and the radiograph tallies.

Highly stable carbon nanotube field emitters on small metal tips against electrical arcing.

Carbon nanotube (CNT) field emitters that exhibit extremely high stability against high-voltage arcing have been demonstrated. The CNT emitters were fabricated on a sharp copper tip substrate that produces a high electric field. A metal mixture composed of silver, copper, and indium micro- and nanoparticles was used as a binder to attach CNTs to the substrate. Due to the strong adhesion of the metal mixture, CNTs were not detached from the substrate even after many intense arcing events. Through electrical conditioning of the as-prepared CNT emitters, vertically standing CNTs with almost the same heights were formed on the substrate surface and most of loosely bound impurities were removed from the substrate. Consequently, no arcing was observed during the normal operation of the CNT emitters and the emission current remained constant even after intentionally inducing arcing at current densities up to 70 mA/cm2.