SOx Functionalized NiOOH Nanosheets Embedded in Ni(OH)2 Microarray for High-Efficiency Seawater Oxidation

A nano-micro heterostructure has been established to address the challenges of selectivity, stress, pitting corrosion, and long-term durability of anodes in unpurified seawater. The heterostructure comprised NiOOH nanosheets embedded within a high surface area Ni(OH)2 microarray, and the surface structure is further functionalized with sulfate (SOx). This cation-selective protective layer impedes chloride (Cl-) diffusion and abstracts H from reaction intermediates, leading to enhanced selectivity and corrosion resistance of the anode. The multilevel porosity within the randomly oriented nanosheets and the underlying support provide short diffusion channels for ions and mass migration, ensuring efficient ion transport and long-term structural and mechanical durability of the active sites, even at high current density. Remarkably, the catalyst requires a small input voltage of 400 mV to deliver a current density of 1 A cm-2 and maintains it for over 168 h without noticeable degradation or hypochlorite formation. Spectroscopic analysis and density functional theory (DFT) calculations reveal that the Ni electronic structure in the +3 valence state, its strong structural interaction with the underlying microarray, and the functionality of SOx significantly reduce the required potential for O-O coupling.

Fetal choroid plexus arteriovenous malformation, masquerading as a neoplastic lesion

A woman in her 20s, who was pregnant, underwent a routine antenatal ultrasound revealing organised intraventricular haemorrhage and a vascular area in the left thalamic region. Fetal MRI raised suspicion of arteriovenous malformation (AVM). The baby was delivered at 36 weeks via C-section, and initial brain MRI suggested a possible neoplastic lesion.Cerebral angiography confirmed a large AVM involving the left choroid plexus with arterial feeders from the left anterior and posterior choroidal arteries and a large venous varix draining into the vein of Galen. Both arterial feeders were successfully embolised with Onyx and glue, achieving complete occlusion.Choroid plexus AVMs are rare and often lead to intraventricular or intraparenchymal haemorrhage. Surgical treatment has shown success, but endovascular management is effective, especially for small, deep-seated AVMs, offering a better prognosis.

Pulmonary barotrauma as a complication of mechanical ventilation for management of COVID-19 associated acute respiratory distress syndrome (CARDS)

Objectives

To identify that incidence of pulmonary barotrauma secondary to mechanical ventilation for the management of acute respiratory distress syndrome associated with coronavirus-disease-2019, and to compare it with the incidence of pulmonary barotrauma trauma secondary to mechanical ventilation associated with all the other causes.

METHODS

The retrospective case-control study was conducted at the Aga Khan University Hospital, Karachi, and comprised data from October 2020 to March 2021 of patients who underwent mechanical ventilation. The data was divided into two groups. Data of acute respiratory distress syndrome associated with coronavirus-disease-2019 was in group 1, and that of acute respiratory distress syndrome associated with any other cause in control group 2. Medical records were reviewed to obtain demographic and clinical data, while the institutional picture archiving and communication system was used to review radiological images. Data was analysed using SPSS 24.

RESULTS

Of the 261 cases, 115(44%) were in group 1; 87(75.6%) males and 28(24.3%) females. There were 146(56%) controls in group 2; 96(65.7%) males and 50(34.2%) females. There were 142(54.4%) subjects aged >60 years; 61(43%) in group 1 and 81(57%) in group 2. The incidence of pulmonary barotrauma in group 1 was 39(34%) and 8(5.5%) in group 2 (p<0.0001).

CONCLUSIONS

Mechanical ventilation in the management of acute respiratory distress syndrome associated with coronavirusdisease- 2019 was found to be associated with a significantly higher incidence of pulmonary barotrauma than acute respiratory distress syndrome associated with any other cause.

Acidified manure and nitrogen-enriched biochar showed short-term agronomic benefits on cotton-wheat cropping systems under alkaline arid field conditions

Application of organic residues such as farm manure and biochar in various agricultural environments have shown positive effects on soil carbon sequestration. However, there is a lack of consensus regarding the agronomical benefits of a single and small dose of biochar and farm manure in arid alkaline soils. Therefore, a field experiment with the given treatments (1) control (no amendment), (2) acidified manure (AM) at 300 kg ha-1, (3) nitrogen (N) enriched biochar (NeB) at 3 Mg ha-1, and (4) an equal combination of AM + NeB (150 kg ha-1 AM + 1.5 Mg ha-1 NeB)) was conducted in a typical cotton-wheat cropping system. A parallel laboratory incubation study with the same amendments was carried out to account for soil carbon dioxide emission (CO2). The N enrichment of biochar and its co-application with acidified manure increased soil mineral N (NO3- and NH4+) in the topsoil (0-15 cm), and increased total N uptake (25.92% to 69.91%) in cotton over control, thus reducing N losses and increased uptake over control. Compared to the control, co-application of AM + NeB significantly improved soil N and P bioavailability, leading to increased plant biomass N, P, and K (32%, 40%, 6%, respectively) uptake over control. The plant's physiological and growth improvements [chlorophyll (+ 28.2%), height (+ 47%), leaf area (+ 17%), number of bolls (+ 7%), and average boll weight (+ 8%)] increased the agronomic yield in the first-season crop cotton by 25%. However, no positive response was observed in the second season wheat crop. This field study improved our understanding that co-application of acidified manure and N-enriched biochar in small dose can be a strategy to achieve short-term agronomic benefits and carbon sequestration in the long run.

Percutaneous endovascular removal of a broken port-a-catheter from right atrium using manual made snare

Fracture and migration of port-a-catheter, following long term access into the central venous vasculature is a rare clinical scenario. The consequences of fracture and migration includes fragmented device relocating into the right atrium or ventricle, eventually causing life threatening complications such as arrhythmias, pseudoaneurysms, perforations or very rarely embolization. We report a case of a 67-year-old female with a broken port-a-catheter which had been placed initially for chemotherapy for bilateral breast cancer. Chest radiograph showed the fragmented catheter had migrated to the right atrium; which was successfully removed via percutaneous radiological endovascular intervention. No immediate post procedure complication was noted.

Insight into UV-induced simultaneous photocatalytic degradation of Ti3C2Tx MXene and reduction of U(VI)

With the development of MXene as the efficient adsorbent for U(VI), the tendency of MXene coming into contact with U(VI) in wastewaters increases. Motivated by UV light irradiation applied in wastewater treatments, the UV light induced photochemical co-transformation of Ti₃C₂T_x MXene and U(VI) is studied. To clarify the role of U(VI) induced Ti₃C₂T_x aggregation in phototransformation of Ti₃C₂T_x, the aggregation kinetics of Ti₃C₂T_x in the presence of various valent radioactive ions are investigated, obtaining the critical coagulation concentrations (CCC) of Ti₃C₂T_x for Cs⁺, Sr²⁺, UO₂²⁺, Eu³⁺, and Th⁴⁺. Besides, the colloidal stability of UV-induced Ti₃C₂T_x as a function of standing time is discussed. The results show that the aggregation behavior of Ti₃C₂T_x induced by radioactive ions follows the classical Derjaguin-Landau-Verwey-Overbeek (DLVO) theory and the Schulze-Hardy rule. The UV irradiation will change the physicochemical properties and colloidal stabilities of Ti₃C₂T_x. Furthermore, the degradation of Ti₃C₂T_x can be accelerated by UV irradiation and further promoted by the presence of U(VI). The removal of U(VI) is highest in the case of Ti₃C₂T_x combined with UV irradiation via adsorption and reduction. This study provides an example demonstrating that the simultaneous transformation of Ti₃C₂T_x (adsorbent) and U(VI) (adsorbate) to mild toxic components.

Electronic and Structural Modification of Mn3O4 Nanosheets for Selective and Sustained Seawater Oxidation

The accomplishment of seawater electrolysis to produce green hydrogen energy needs an efficient and durable electrocatalyst with high selectivity and corrosion resistance. Here we report a free-standing amorphous nanostructured oxygen evolution reaction (OER) electrocatalyst with microvoids developed by embedding Gd-doped Mn₃O₄ nanosheets in a CuO-Cu(OH)₂ nanostructure array (Gd-Mn₃O₄@ CuO-Cu(OH)₂. The surface oxygen vacancies modulated the electronic structure of the catalyst and offered active sites with optimal chemisorption energy to OER intermediates. The hierarchical surface structure provides a large specific surface area, high electrical conductivity, ionic mobility, intrinsic activity for each active site, and efficient charge transfer, leading to an outstanding catalytic performance. The enhanced structural, chemical, and corrosion resistance ensures effectiveness as an anode in direct seawater electrolysis. Specifically, it needs an input voltage of 1.63 V to deliver a current density of 500 mA cm^-2 in alkaline seawater, with the stability of more than 75 h of continuous electrolysis without hypochlorite formation. The high Faradaic efficiency demonstrates its potential for hydrogen fuel production from seawater.

Beneficial effects of coconut oil (Cocos nucifera) on hematobiochemicl and histopathological markers in CCL4-intoxicated rabbits

The study was designed to investigate the effect of Coconut Oil on the levels of some liver and hematological parameters in carbon tetrachloride intoxicated rabbits. Also the antioxidant capacity of Coconut Oil for various concentrations was assessed on the basis of percent scavenging of (DPPH) free radical. Experimental animals were divided into five groups, eight rabbits in each group. These were: group A (Normal control), group B (Toxic control), group C (Standard control), group D (Treated with Coconut Oil 50 mL/kg body weight after CCl4 intoxication), group E (Treated with Coconut Oil 200 mL/kg body weight after CCl4 intoxication). The effects observed were compared with a standard hepatoprotective drug silymarine (50 mL/kg body weight). The Coconut Oil (200 mL/kg body weight) significantly (P<0.05) reduced the elevated serum levels of alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP) when compared to a toxic control rabbits. The results of extract treated rabbits were similar to silymarine administered rabbits group. Treatment with Coconut Oil root and silymarine caused no significant changes in RBC, Platelets, (Hb), (MCH) concentration and (HCT) values. However, significant (P<0.05) increase was observed in the total WBC count. The present study suggested that Coconut Oil can be used as an herbal alternative (need further exploration i.e to detect its bioactive compound and its efficacy) for hepatoprotective activity.

Correlation Of Computerized Tomography (CT) Severity Score For COVID-19 Pneumonia With Clinical Outcomes

BACKGROUND

Though various computerized tomography (CT) severity scores have been described for risk prognostication for coronavirus disease 2019 (COVID-19), most are challenging to calculate and have variable inter-observer agreement. The objective of this study was to develop a simple CT severity score (CT-SS) with good inter-observer agreement and assess its correlation with clinical outcome.

METHODS

This retrospective study was conducted at the Aga Khan University Hospital (AKUH), from April-August 2020. All patients who were PCR positive for COVID-19 and underwent CT chest examination at AKUH were included. Severity of disease was described on the basis of a 10-point CT severity score (CT-SS) devised at our institution. CT-SS were categorized as Low (0-7) and High (8-10). Inter-observer reliability between radiologist and COVID-19 intensivist was assessed using the Kappa statistic.

RESULTS

A total of 73 patients were included, the majority male (58.9%) with mean age 55.8±13.93 years. The CT-SS rated on 0-10 showed substantial inter-observer reliability between radiologist and intensivist with a Kappa statistic of 0.78. Patients with CT-SS 8-10 had a significantly higher ICU admission & intubation rate (53.8% vs. 23.5%) and mortality rate (35.9% vs. 11.8%; p=0.017), as compared to those with CT-SS 0-7.

CONCLUSIONS

We conclude that the described CT severity score (CT-SS) is a quick, effective, and easily reproducible tool for prediction of adverse clinical outcome in patients with COVID 19 pneumonia. The tool shows good inter-observer agreement when calculated by radiologist and physician independently.

Photocatalytic Z-Scheme Overall Water Splitting: Recent Advances in Theory and Experiments

Photocatalytic water splitting is considered one of the most important and appealing approaches for the production of green H₂ to address the global energy demand. The utmost possible form of artificial photosynthesis is a two-step photoexcitation known as "Z-scheme", which mimics the natural photosystem. This process solely relies on the effective coupling and suitable band positions of semiconductors (SCs) and redox mediators for the purpose to catalyze the surface chemical reactions and significantly deter the backward reaction. In recent years, the Z-scheme strategies and their key role have been studied progressively through experimental approaches. In addition, theoretical studies based on density functional theory have provided detailed insight into the mechanistic aspects of some breathtakingly complex problems associated with hydrogen evolution reaction and oxygen evolution reaction. In this context, this critical review gives an overview of the fundamentals of Z-scheme photocatalysis, including both theoretical and experimental advancements in the field of photocatalytic water splitting, and suggests future perspectives.

Mosquitocidal activities of Chenopodium botrys whole plant n-hexane extract against Culex quinquefasciatus

This research aimed to investigate various mosquitocidal activities of Chenopodium botrys whole- plant n-hexane extract against Culex quinquefasciatus. The extract showed remarkable larvicidal, pupicidal, adulticidal, oviposition deterrent and adult emergence inhibitory activities against Cx. quinquefasciatus. During the larvicidal and pupicidal activities, the 24-hour lethal concentration (LC50) of extract against 2nd instar larvae, 4th instar larvae and pupae were 324.6, 495.6 and 950.8 ppm, respectively. During the CDC (Centers for Disease Control and Prevention) bottle bioassay for adulticidal activity, the median knockdown times (KDT50) at 1.25% concentration was 123.4 minutes. During the filter paper impregnation bioassay for adulticidal activity, the KDT50 value at 0.138 mg/cm2 concentration was 48.6 minutes. The extract was fractionated into 14 fractions through silica gel column chromatography which were then combined into six fractions on the basis of similar retention factor (Rf) value. These fractions were screened for adulticidal activity by applying CDC bottle bioassay. The fraction obtained through 60:40 to 50:50% n-hexanes-chloroform mobile phase with 0.5 Rf value showed 100% adulticidal activity at 0.2% concentration. During oviposition deterrent activity, the highest concentration (1000 ppm) showed 71.3 ± 4.4% effective repellence and 0.6 ± 0.1 oviposition activity index. During adult emergence inhibition activity, the median emergence inhibition (EI50) value was 312.3 ppm. From the outcome of the present investigation, it is concluded that the n-hexane extract of C. botrys whole- plant possesses strong larvicidal, pupicidal, adulticidal, oviposition deterrent and adult emergence inhibitory activities against Cx. quinquefasciatus.

To determine the efficacy of bilateral inferior petrosal sinus sampling in differentiating Cushing disease from ectopic Cushing syndrome

Management of endogenous Cushing syndrome is based on its aetiology. Increased Adrenocorticotropic Hormone (ACTH) levels are the most common cause of this disorder and, therefore, it is critical to determine the source of ACTH before further management. Dynamic post contrast MRI is currently the most common investigation implied to diagnose pituitary adenoma; however, it comes with the drawback of low specificity and high false positive results. Inferior petrosal sinus sampling (IPSS) is an established invasive procedure performed to differentiate central versus peripheral source of ACTH which, in turn, results in hypercortesolaemia. This is a series of 14 patients who underwent IPSS at the Department of Radiology, Aga Khan University Hospital, Karachi, from January 2006 to December 2018. The case series emphasises the role of IPSS in the management of ACTH-dependent Cushing syndrome and combined efficacy of Dynamic post-contrast MRI and the procedure under focus.

Endovascular coil embolization of ruptured and unruptured intracranial aneurysms: review of a 15 year single center experience in Pakistan

OBJECTIVE

To assess the outcome of endovascular treatment of intracranial aneurysm over 15 years.

METHODS

The retrospective study was conducted at the at Radiology Department of Aga Khan University Hospital, Karachi, and comprised medical records from April 2003 to April 2018 of patients who received endovascular treatment for intracranial aneurysm. Multiple variables reviewed included demographics, clinical presentation, aneurysm morphology, technique used, technique outcome and clinical outcome. Data was analysed using SPSS 22.

RESULTS

Of the 242 patients, 111(45.8%) were males and 131(54.1%) were female. The overall mean age was 46.3+/-13.543 years (range: 9-78years). Aneurysm size was <5mm in 95(40.4%) patients, 5-10mm in 98(41.7%) and >10mm in 42(17.9%) patients. Aneurysms were located in the anterior communicating artery in 93(38.4%) patients, internal carotid artery 48(19.8%) patients and posterior communicating artery 26(10.7%) patients. Patients with higher initial Hess and Hunt grade were more likely to have higher modified Rankin scale score after treatment (p=0.001). Overall, 222(91.7%) patients were treated successfully. Complications were noted in 37(15.2%) patients and 10(4.0%) patients died.

CONCLUSIONS

No correlation was found between Hess and Hunt grades and aneurysm severity based on aneurysm size, neck and ruptured/unruptured cases.

Gd-Doped Ni-Oxychloride Nanoclusters: New Nanoscale Electrocatalysts for High-Performance Water Oxidation through Surface and Structural Modification

Oxygen evolution reaction (OER) is a bottleneck process in the water-splitting module for sustainable and clean energy production. Transition metal-based electrocatalysts can be effective as water-splitting catalytic materials because of their appropriate redox properties and natural abundance, but the slow kinetics because of strong adsorption and consequently slow desorption of intermediates on the active sites of catalysts severely hamper the dynamics of the released molecular oxygen and thus remains a formidable challenge. Herein, we report the development of structurally and surface-modified PA-Gd-Ni(OH)₂Cl (partially alkylated gadolinium-doped nickel oxychloride) nanoclusters (NCs, size ≤ 3 nm) for enhanced and stable OER catalysis at low overpotential and high turnover frequency. The ameliorated catalytic performance was achieved by controlling the surface coverage of these NCs with hydrophobic ligands and through the incorporation of electronegative atoms to facilitate easy adsorption/desorption of intermediates on the catalyst surface, thus improving the liberation of O₂. Such a surface and structural modification and uniform distribution at the nanoscale length are indeed worth considering to selectively tune the catalytic potential and further modernize the electrode materials for the challenging OER process.

Comparison of the Efficacy of Tramadol and Paroxetine in the Management of Premature Ejaculation

Objective

The goal of this study was to compare the efficacy of tramadol and paroxetine in the treatment of primary premature ejaculation (PE).

Study design

This study was a randomized controlled trial performed in the outpatient department of Nishtar Hospital, Multan, from January 2017 to January 2018.

Methodology

One hundred six patients were diagnosed with PE and included in the study. The patients were categorized into two groups receiving either tramadol or paroxetine through a lottery randomization method. The main variables were baseline PE, baseline satisfaction after intercourse, baseline intravaginal ejaculatory latency time (IELT), ejaculation control, difficulty in ejaculation, and after-treatment satisfaction with sexual intercourse and IELT. We used IBM SPSS Statistics for Windows, Version 23.0 (Armonk, NY: IBM Corp.) for data analysis, and p≤0.05 was considered statistically significant.

Results

Ejaculation control, difficulty in ejaculation, and distress due to ejaculation in patients in the tramadol group was noted as 24.5%, 7.5%, and 7.5%, respectively. Ejaculation control, difficulty in ejaculation, and distress due to ejaculation in the paroxetine group was noted as 49.1%, 17%, and 24.5%, respectively. The differences were statistically significant within the groups at baseline and after treatment of PE (p<0.001).

Conclusion

Tramadol is an effective and useful drug as compared to paroxetine for the treatment of PE. Tramadol can be used as an alternative to other medications for the treatment of lifelong PE.

Controlled Assembly of Cu/Co-Oxide Beaded Nanoclusters on Thiolated Graphene Oxide Nanosheets for High-Performance Oxygen Evolution Catalysts

The use of water splitting modules is highly desired for the sustainable production of H₂ as a future energy carrier. However, the sluggish kinetics and demand of high anodic potential are the bottlenecks for half-the cell oxygen evolution reaction (OER), which severely hamper the overall conversion efficiency. Although transition metal oxides based electrocatalysts have been envisioned as cost-effective and potential contenders for this quest, nevertheless, their low conductivity, instability, and limited number of active sites are among the common impediments that need to be addressed to eventually enhance their inherent catalytic potential for enhanced OER activity. Herein, the controlled assembly of transition metal oxides, that is, Cu@CuO_x nanoclusters (NCs, ≈2 nm) and Co@CoO_x beaded nanoclusters (BNCs, ≈2 nm), on thiol-functionalized graphene oxide (G-SH) nanosheets is reported to form novel and highly efficient electrocatalysts for OER. The thiol (-SH) functionality was incorporated by selective epoxidation on the surface of graphene oxide (GO) to achieve chemically exfoliated nanosheets to enhance its conductivity and trapping ability for metal oxides in nanoscale dimensions (≈2 nm). During the electrocatalytic reaction, overpotentials of 290 mV and 310 mV are required to achieve a current density of 10 mA cm^-2 for BNCs and NCs, respectively, and the catalysts exhibit tremendous long-term stability (≈50 h) in purified alkaline medium (1 m KOH) with no dissolution in the electrolyte. Moreover, the smaller Tafel slopes (54 mV/dec for BNCs and 66 mV/dec for NCs), and a Faradic efficiency of approximately 96 % indicate not only the selectivity but also the tailored heterogeneous electrons transfer (HET) rate, which is required for fast electrode kinetics. It is anticipated that such ultrasmall metal oxide nanoclusters and their controlled assembly on a conducting surface (G-SH) may offer high electrochemical accessibility and a plethora of active sites owing to the drastic decrease in dimensions and thus can synergistically ameliorate the challenging OER process.

Super Wide Band, Defected Ground Structure (DGS), and Stepped Meander Line Antenna for WLAN/ISM/WiMAX/UWB and other Wireless Communication Applications

This paper presents a new shape (s-shape monopole) of a super wideband antenna using stepped meander lines, a quarter waveguide transformer feeding line, and a defected ground structure (DGS). The antenna will be used for multiple wireless communication applications like WIMAX/WLAN/ISM/UWB, and also for several wireless communication applications. The total dimensions of the proposed antenna are 35 mm × 35 mm × 1.57 mm or 0.36 λo × 0.36 λo × 0.016 λo, which are the corresponding electrical dimensions with free-space wavelength (λo) at the lower operating frequency. The antenna is designed and simulated into two steps: the first (Antenna 1) covers a bandwidth of 18.2 GHz, while the second (Antenna 2, using DGS) covers a super wide bandwidth of 37.82 GHz (3.08-40.9 GHz). The measured fractional bandwidth and bandwidth ratio of the antenna are 174.68% and 13.009:1, respectively, which is operating from 3.09-40.2 GHz. The maximum calculated gain and efficiency are 5.9 dBi and 92.7%, respectively. The time-domain performance is good due to the calculation of the system fidelity factor, group delay, and its linear and constant phase variation.

High Efficient and Ultra Wide Band Monopole Antenna for Microwave Imaging and Communication Applications

The paper presents a highly efficient, low cost, ultra-wideband, microstrip monopole antenna for microwave imaging and wireless communications applications. A new structure (z-shape, ultra-wideband (UWB) monopole) is designed, which consists of stepped meander lines to achieve super-wide bandwidth and high efficiency. Three steps are used to design the proposed structure for the purpose to achieve high efficiency and wide bandwidth. The antenna bandwidth is enhanced by varying the length of meander line slots, optimization of the feeding line and with the miniaturization of the ground width. The simulated and measured frequency bands are 2.7-22.5 GHz and 2.8-22.7 GHz (156% fractional bandwidth), respectively. The dimensions of the antenna are 38 mm × 35 mm × 1.57 mm, and its corresponding electrical size is 2.41 λg × 2.22 λg × 0.09 λg, where guided wavelength λg is at the center frequency (12.75 GHz). This antenna achieved a high bandwidth ratio (8.33:1). The realized gain is varying from 1.6-6.4 dBi, while that of efficiency is 70% to 93% for the whole band. Radiation patterns are measured at four operating frequencies. It has an acceptable group delay, fidelity factor, and phase variation results that satisfy the limit of ultra-wideband in the form of the time domain.

Ultrasmall Co@Co(OH)2 Nanoclusters Embedded in N-Enriched Mesoporous Carbon Networks as Efficient Electrocatalysts for Water Oxidation

Metal nanoclusters (NCs, size ≤2 nm) are emerging materials in catalysis owing to their unique catalytic and electronic properties such as high surface/volume ratio, high redox potential, plethora of surface active sites, and dynamic behavior on a suitable support during catalysis. Herein, in situ growth of ultrasmall and robust Co@β-Co(OH)₂ NCs (≈2 nm) hosted in a honeycomb-like 3D N-enriched carbon network was developed for water-oxidation catalysis with extremely small onset potential (1.44 V). Overpotentials of 220 and 270 mV were required to achieve a current density of 10 mA cm^-2 and 100 mA cm^-2 , respectively, in alkaline medium (1 m KOH). More promisingly, at η₁₀ =240 mV, the prolonged oxygen evolution process (>130 h) with faradaic efficiency >95 % at a reaction rate of 22 s^-1 at 1.46 V further substantiated the key role of the ultrasmall supported NCs, which outperformed the benchmark electrocatalysts (RuO₂ /IrO₂ ) and NCs reported so far. It is anticipated that the high redox potential of NCs with regeneratable active sites and their concerted synergistic effects with the N-enriched porous/flexible carbon network are inherently worth considering to enhance the mass/charge transport owing to the nanoscale interfacial collaboration across the electrode/electrolyte boundary, thereby efficiently energizing the sluggish/challenging oxygen evolution process.

Complementary Metamaterial Sensor for Nondestructive Evaluation of Dielectric Substrates

In this paper, complementary metamaterial sensor is designed for nondestructive evaluation of dielectric substrates. The design concept is based on electromagnetic stored energy in the complementary circular spiral resonator (CCSR), which is concentrated in small volume near the host substrate at resonance. This energy can be employed to detect various electromagnetic properties of materials under test (MUT). Effective electric permittivity and magnetic permeability of the proposed sensor is extracted from scattering parameters. Sensitivity analysis is performed by varying the permittivity of MUT. After sensitivity analysis, a sensor is fabricated using standard PCB fabrication technique, and resonance frequency of the sensor due to interaction with different MUT is measured using vector network analyzer (AV3672series). The transcendental equation is derived for the fabricated sensor to calculate relative permittivity for unknown MUTs. This method is very simple and requires calculating only the resonant frequency, which reduces the cost and computation time.

Metal Nanoclusters: New Paradigm in Catalysis for Water Splitting, Solar and Chemical Energy Conversion

A sustainable future demands innovative breakthroughs in science and technology today, especially in the energy sector. Earth-abundant resources can be explored and used to develop renewable and sustainable resources of energy to meet the ever-increasing global energy demand. Efficient solar-powered conversion systems exploiting inexpensive and robust catalytic materials for the photo- and photo-electro-catalytic water splitting, photovoltaic cells, fuel cells, and usage of waste products (such as CO₂ ) as chemical fuels are appealing solutions. Many electrocatalysts and nanomaterials have been extensively studied in this regard. Low overpotentials, catalytic stability, and accessibility remain major challenges. Metal nanoclusters (NCs, ≤3 nm) with dimensions between molecule and nanoparticles (NPs) are innovative materials in catalysis. They behave like a "superatom" with exciting size- and facet-dependent properties and dynamic intrinsic characteristics. Being an emerging field in recent scientific endeavors, metal NCs are believed to replace the natural photosystem II for the generation of green electrons in a viable way to facilitate the challenging catalytic processes in energy-conversion schemes. This Review aims to discuss metal NCs in terms of their unique physicochemical properties, possible synthetic approaches by wet chemistry, and various applications (mostly recent advances in the electrochemical and photo-electrochemical water splitting cycle and the oxygen reduction reaction in fuel cells). Moreover, the significant role that MNCs play in dye-sensitized solar cells and nanoarrays as a light-harvesting antenna, the electrochemical reduction of CO₂ into fuels, and concluding remarks about the present and future perspectives of MNCs in the frontiers of surface science are also critically reviewed.

High-Sensitivity Microwave Sensor for Liquid Characterization Using a Complementary Circular Spiral Resonator

This paper describes a low-cost, small size, and high-sensitivity microwave sensor using a Complementary Circular Spiral Resonator (CCSR), which operates at around 2.4 GHz, for identifying liquid samples and determining their dielectric constants. The proposed sensor was fabricated and tested to effectively identify different liquids commonly used in daily life and determine the concentrations of various ethanol–water mixtures at by measuring the resonant frequency of the CCSR. Using acrylic paint, a square channel was drawn at the most sensitive position of the microwave sensor to ensure accuracy of the experiment. To estimate the dielectric constants of the liquids under test, an approximate model was established using a High-Frequency Simulator Structure (HFSS). The results obtained agree very well with the existing data. Two parabolic equations were calculated and fitted to identify unknown liquids and determine the concentrations of ethanol–water mixtures. Thus, our microwave sensor provides a method with high sensitivity and low consumption of material for liquid monitoring and determination, which proves the feasibility and broad prospect of this low-cost system in industrial application.

Role of assessment for retreatment with Transarterial chemoembolization score in decision of Retreatment with trans-arterial chemo-embolization Sessions in patients with hepatocellular carcinoma

BACKGROUND

The objective behind this study was to determine that Assessment for Retreatment with Transarterial chemoembolization (ART) score is really applicable in patients with hepatocellular carcinoma.

METHODS

A cross sectional observational study was conducted on all patients with hepatocellular carcinoma of intermediate stage and undergone ≥2 Transarterial chemoembolization. ART score was assessed before and after each session of Transarterial chemoembolization. Multi-logistic regression analysis was performed to compare the final outcome of patients with ART score of ≥2.5 into groups with two and more than two Trans-arterial chemo-embolization sessions.

RESULTS

A total of 100 HCC patients were recruited for final analysis. Our study participants consisted of total 100 HCC patients. Mean Child Pugh score was 6.1±0.95. In our study, most of the study participants (n=63) had ART score of less than 1.5 as compared to ART score >2.5 (n=37). A significant proportion of patients with ART score of <1.5 prior to second Trans-arterial chemo-embolization had better median survival as compared to patients with ART score of >2.5, p-value<0.001. Patients with ART score of more than 2.5 did not show any survival benefit after having 3rd or 4th Trans-arterial chemo-embolization session, p=0.47.

CONCLUSIONS

Our study findings suggest that those HCC patients who receive multiple sessions of TACE with a low ART score have more favourable outcomes with increased survival rate.

Pulmonary arteriovascular malformation: a rare cause of unexplained hypoxia and acute dyspnoea in young patients

Pulmonary arteriovenous malformations (PAVMs) are anomalous vascular connections between arteries and veins in the lung and comprise of two types, simple and complex. PAVMs are associated with congenital conditions such as hereditary haemorrhagic telengiectasia along with acquired causes. We present a case of a 26-year-old man who presented with dyspnoea, palpitations and decreased oxygen saturation as an initial presentation of PAVM, which was treated successively with embolisation.

Reliability of ion accumulation and growth components for selecting salt tolerant lines in large populations of rice

Ion accumulation and growth under salt stress was studied in two experiments in a rice mapping population derived from parents CO39 and Moroberekan with 4-fold differences in shoot Na+ accumulation. The 120 recombinant inbred lines (RILs) had differences up to 100-fold in Na+. Measurement of 'salt tolerance' (biomass production of the RILs in 100mM NaCl relative to controls) after 42 days showed a 2-fold variation in 'salt tolerance' between parents, with five RILs being more tolerant than the more tolerant parent CO39. The reliability of various traits for selecting salt tolerance in large populations was explored by measuring Na+, K+ and K+/Na+ ratios in leaf blades and sheaths after 7 or 21 days of exposure to 100mM NaCl, and their correlation with various growth components and with leaf injury. The highest correlations were found for Na+ in the leaf blade on day 21 with injury at day 42 in both experiments (r=0.7). Earlier measurements of Na+ or of injury had lower correlations. The most sensitive growth components were tiller number plant-1 and shoot water content (g water g-1 dry weight), and these were correlated significantly with Na+ and, to a lesser extent, with K+/Na+. These studies showed that exposure for at least 42 days may be needed to clearly demonstrate the beneficial effect of the trait for Na+ exclusion on growth under salinity.

Successful percutaneous angioembolisation of bleeding jejunal varix by acrylate glue and coils

Portal hypertension is a common disease worldwide. One of its rare complications is bleeding jejunal varices which is usually asymptomatic and may present with gastrointestinal bleeding. We present a case of a jejunal bleeding that was successfully embolised with acrylate glue and embolisation coils. A middle-aged woman with a history of multiple abdominal surgeries for adenocarcinoma of right ovary, presented to us with multiple episodes of haematochezia. On a CT scan of the abdomen, she was diagnosed with chronic liver disease with portal hypertension, multiple varices at porto-systemic anastomosis and ectopic jejunal varix. She was treated by interventional radiologists by percutaneous embolisation of bleeding varix using glue and embolisation coils through a portal venous approach.

Hepatocellular carcinoma in Native South Asian Pakistani population; trends, clinico-pathological characteristics & differences in viral marker negative & viral-hepatocellular carcinoma

BACKGROUND

HCC is the fifth most common cancer globally. Our study was conducted to (1)investigate the trends and clinico-pathological characteristics of Hepatocellular carcinoma among native South Asian patients in Pakistan, (2)to estimate the prevalence as well as the trends of viral marker negative HCC and (3) to compare the clinico-pathological, radiological characteristics, applicability of treatment at diagnosis and prognostic factors among patients with both viral marker negative and viral marker positive-HCC being consulted at Aga Khan University Hospital(AKUH), Karachi, Pakistan.

METHOD

Patients ≥18 years, already diagnosed to have HCC and visiting AKUH during 1999-2009 were identified using ICD code 1550. The diagnosis of HCC was made in the presence of characteristic features of HCC on triple-phasic CT scan/MRI or with histological findings on biopsy.

RESULTS

645 patients were enrolled. Of these 546(84.7%) were viral-HCC and 99(15.3%) were viral marker negative HCC. Among viral-HCC group underlying etiology of cirrhosis was HCV in 67.9%, HBV in 21.8% and concomitant HBV with HCV or HDV in 10.3% cases. Majority (62.8%) patients had advanced HCC. Larger tumor size (p < 0.001), shorter duration between diagnosis of cirrhosis and HCC (p 0.03), concomitant Diabetes Mellitus (p < 0.001) were found significant factors associated with viral marker negative HCC.

CONCLUSION

The burden of hepatocellular carcinoma is rising among native South Asian Pakistani population and the viral marker negative HCC are not uncommon in our population. Viral marker negative HCC tend not to be under surveillance as compared to viral-HCC and are diagnosed mostly at advanced stage & when they became symptomatic.

Atypical focal nodular hyperplasia of the liver

BACKGROUND

Focal nodular hyperplasia, a benign hepatic tumor, is usually asymptomatic. However, rarely the entity can cause symptoms, mandating intervention.

METHOD

We present a case of focal nodular hyperplasia of the liver, which caused a considerable diagnostic dilemma due to its atypical presentation.

RESULTS

A 29-year-old woman presented with a 15-year history of a progressively increasing mass in the right upper quadrant which was associated with pain and emesis. Examination showed a firm, mobile mass palpable below the right subcostal margin. A computed tomography scan of the abdomen showed an exophytic mass arising from hepatic segments III and IVb. Trucut biopsy of the hepatic mass was equivocal. Angiography showed a vascular tumor that was supplied by a tortuous branch of the proper hepatic artery. Surgical intervention for removal of the mass was undertaken. Intra-operatively, two large discrete tumors were found and completely resected. Histopathological examination showed features consistent with focal nodular hyperplasia.

CONCLUSION

This description of an unusual case of focal nodular hyperplasia of the liver highlights the point that the diagnosis of otherwise benign hepatic tumors may be difficult despite extensive work-up in some cases.

Cerebral venous system anatomy

Cerebral venous system can be divided into a superficial and a deep system. The. superficial system comprises of sagittal sinuses and cortical veins and these drain superficial surfaces of both cerebral hemispheres. The deep system comprises of lateral sinus, straight sinus and sigmoid sinus along with draining deeper cortical veins. Both these systems mostly drain themselves into internal jugular veins. The veins draining the brain do not follow the same course as the arteries that supply it. Generally, venous blood drains to the nearest venous sinus, except in the case of that draining from the deepest structures, which drain to deep veins. These drain, in turn, to the venous sinuses. The superficial cerebral veins can be subdivided into three groups. These are interlinked with anastomotic veins of Trolard and Labbe. However, the superficial cerebral veins are very variable. They drain to the nearest dural sinus. Thus the superolateral surface of the hemisphere drains to the superior sagittal sinus while the posteroinferior aspect drains to the transverse sinus. The veins of the posterior fossa are variable in course and angiographic diagnosis of their occlusion is extremely difficult. Blood from the deep white matter of the cerebral hemisphere and from the basal ganglia is drained by internal cerebral and basal veins, which join to form the great vein of Galen that drains into the straight sinus. With the exception of wide variations of basal vein, the deep system is rather constant compared to the superficial venous system. Hence their thrombosis is easy to recognize.

Transcatheter embolization of acute non-variceal gastrointestinal hemorrhage

OBJECTIVE

To determine the efficacy and safety of transcatheter embolization of nonvariceal gastrointestinal hemorrhage.

DESIGN

Descriptive analytical study.

PLACE AND DURATION OF STUDY

Radiology Department, The Aga Khan University Hospital, Karachi, Pakistan, from October 1999 to August 2004.

SUBJECTS AND METHODS

The study included 27 patients who underwent angiography for suspected gastrointestinal hemorrhage. The presumptive diagnosis was based on the findings of endoscopy in 08 patients, scintigraphy in 05 patients and on clinical findings only in 14 patients. Nine patients had gastroduodenal hemorrhage, 04 patients had hemobilia and 14 patients had lower gastrointestinal bleeding. Five patients had comorbidities. One patient had uremia, 2 had hepatitis C, 1 had cirrhosis and 1 had coagulopathy. Technical success, clinical success, complications and patient survival were assessed.

RESULTS

Nine patients had upper gastrointestinal hemorrhage, 4 patients had hemobilia and 14 patients had lower gastrointestinal bleeding. Etiology of bleeding was known in 15 patients and unknown in 12 patients. Clinical success was achieved in 23 (85.18%) of 27 patients. Two patients had early rebleeding. One of these was managed surgically and recovered. The other had severe coagulopathy and was unfit for surgery. Two patients had bowel infarction, one of these was managed surgically and recovered and the other died of complication of procedure. One patient had small splenic infarcts and was managed conservatively. Overall 85.18% success was achieved for the embolization procedure. Two of 27 patients died. One patient died because of recurrence of bleeding and other died because of infarction of right hemi-colon which occurred as complication of embolization.

CONCLUSION

Transcatheter embolization is effective and safe in patients with nonvariceal gastrointestinal hemorrhage.

Radiologic feeding gastrostomy placement: experience in 23 patients

OBJECTIVE

To evaluate the safety, efficacy and complications of percutaneous gastrostomy catheter placementunder flouro guidance for long-term enteral feeding.

MATERIALS AND METHODS

Between April 1998 to May 2002, 23 patients who had percutaneous gastrostomy catheter placement were retrospectively reviewed. Clinical indications for catheter placement included patients with neurologic disease, head and neck malignancy, and pulmonary disease patients. Placement of 12 - 14 Fr gastrostomy catheter was then accomplished with the Seldinger technique. The technical success, procedural complications were recorded.

RESULTS

Twenty seven procedures, including revisions, were performed. The success rate for catheter placement was 100%. Revision was necessary in 7 (30%) instances in 7 patients. There was one (3.8%) major and 4 (14.8%) minor complications.

CONCLUSION

Fluoroscopically directed percutaneous placement of gastrostomy catheters is a safe and effective procedure.

Percutaneous transhepatic biliary stenting

OBJECTIVE

Bilary stenting with endoprosthesis is a palliative procedure to relieve malignant biliary obstruction. Percutaneous transhepatic technique has been employed whenever endoscopic technique was not possible or had failed.

SETTING

Angiography/intervention suite, department of radiology, Aga Khan University hospital, Karachi.

METHODS

We present retrospective analysis of 17 patients with malignant jaundice who were treated with percutaneous techniques after the endoscopic route had failed.

RESULTS

The success rate was 94% with placement of single plastic stent in 14 patients, double stents in 3 patients and self-expandable stent in one patient. The overall complication rate was 41% including sepsis, liver abscess, biloma formation, biliary leakage and stent occlusion. There was one procedure related death due to severe sepsis.

CONCLUSION

Percutaneous transhepatic biliary stenting is an alternative procedure to relieve malignant biliary obstruction with high complication rate and should be reserved for selected patients in whom endoscopic route has failed.

The effect of pre-anaesthetic fasting on blood glucose level in children undergoing surgery

Blood glucose concentrations were measured in 104 children aged 6 months- 10 years (mean 3.1 years) undergoing inpatient anaesthesia. The mean fasting period was 10.87 +/- 2.68 hours. Mean preanaesthetic and 1/2 hour post-anaesthetic blood glucose levels were 4.8 +/- 0.8 and 6.1 +/- 1.9 mmoles/L respectively. Pre- anaesthetic low blood glucose level (2.7-3.3 mmoles/L) could only be detected in 3.8% cases. Post-anaesthetic increase in blood glucose level was the same as reported in adults.