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.

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@CuOx nanoclusters (NCs, ≈2 nm) and Co@CoOx 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.

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@ß-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.

Root vacuolar Na+ sequestration but not exclusion from uptake correlates with barley salt tolerance.

Soil salinity is a major constraint for the global agricultural production. For many decades, Na+ exclusion from uptake has been the key trait targeted in breeding programs; yet, no major breakthrough in creating salt-tolerant germplasm was achieved. In this work, we have combined the microelectrode ion flux estimation (MIFE) technique for non-invasive ion flux measurements with confocal fluorescence dye imaging technique to screen 45 accessions of barley to reveal the relative contribution of Na+ exclusion from the cytosol to the apoplast and its vacuolar sequestration in the root apex, for the overall salinity stress tolerance. We show that Na+ /H+ antiporter-mediated Na+ extrusion from the root plays a minor role in the overall salt tolerance in barley. At the same time, a strong and positive correlation was found between root vacuolar Na+ sequestration ability and the overall salt tolerance. The inability of salt-sensitive genotypes to sequester Na+ in root vacuoles was in contrast to significantly higher expression levels of both HvNHX1 tonoplast Na+ /H+ antiporters and HvVP1 H+ -pumps compared with tolerant genotypes. These data are interpreted as a failure of sensitive varieties to prevent Na+ back-leak into the cytosol and existence of a futile Na+ cycle at the tonoplast. Taken together, our results demonstrated that root vacuolar Na+ sequestration but not exclusion from uptake played the main role in barley salinity tolerance, and suggested that the focus of the breeding programs should be shifted from targeting genes mediating Na+ exclusion from uptake by roots to more efficient root vacuolar Na+ sequestration.

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.

Characterization of the multigene family TaHKT 2;1 in bread wheat and the role of gene members in plant Na(+) and K(+) status.

BACKGROUND: A member of the TaHKT2;1 multigene family was previously identified as a Na(+) transporter with a possible role in root Na(+) uptake. In the present study, the existing full-length cDNA of this member was used as a basis to query the International Wheat Genome Survey Sequence to identify all members of the TaHKT2;1 family. Individual TaHKT2;1 genes were subsequently studied for gene and predicted protein structures, promoter variability, tissue expression and their role in Na(+) and K(+) status of wheat. RESULTS: Six TaHKT2;1 genes were characterized which included four functional genes (TaHKT2;1 7AL-1, TaHKT2;1 7BL-1, TaHKT2;1 7BL-2 and TaHKT2;1 7DL-1) and two pseudogenes (TaHKT2;1 7AL-2 and TaHKT2;1 7AL-3), on chromosomes 7A, 7B and 7D of hexaploid wheat. Variability in protein domains for cation specificity and in cis-regulatory elements for salt response in gene promoters, were identified amongst the functional TaHKT2;1 members. The functional genes were expressed under low and high NaCl conditions in roots and leaf sheaths, but were down regulated in leaf blades. Alternative splicing events were evident in TaHKT2;1 7AL-1. Aneuploid lines null for each functional gene were grown in high NaCl nutrient solution culture to identify potential role of each TaHKT2;1 member. Aneuploid lines null for TaHKT2;1 7AL-1, TaHKT2;1 7BL-1 and TaHKT2;1 7BL-2 showed no difference in Na(+) concentration between Chinese Spring except for higher Na(+) in sheaths. The same aneuploid lines had lower K(+) in roots, sheath and youngest fully expanded leaf but only under high (200 mM) NaCl in the external solution. There was no difference in Na(+) or K(+) concentration for any treatment between aneuploid line null for the TaHKT2;1 7DL-1 gene and Chinese Spring. CONCLUSIONS: TaHKT2;1 is a complex family consisting of pseudogenes and functional members. TaHKT2;1 genes do not have an apparent role in controlling root Na(+) uptake in bread wheat seedlings under experimental conditions in this study, contrary to existing hypotheses. However, TaHKT2;1 genes or, indeed other genes in the same chromosome region on 7AL, are candidates that may control Na(+) transport from root to sheath and regulate K(+) levels in different plant tissues.

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.

Treatment of nonvariceal gastrointestinal hemorrhage by transcatheter embolization.

Purpose. To investigate the sensitivity of mesenteric angiography, technical success of hemostasis, clinical success rate, and complications of transcatheter embolization for the treatment of acute nonvariceal gastrointestinal hemorrhage. Material and Methods. A retrospective review of 200 consecutive patients who underwent mesenteric arteriography for acute nonvariceal gastrointestinal hemorrhage between February 2004 and February 2011 was done. Results. Of 200 angiographic studies, 114 correctly revealed the bleeding site with mesenteric angiography. 47 (41%) patients had upper gastrointestinal hemorrhage and 67 (59%) patients had lower gastrointestinal hemorrhage. Out of these 114, in 112 patients (98%) technical success was achieved with immediate cessation of bleeding. 81 patients could be followed for one month. Clinical success was achieved in 72 out of these 81 patients (89%). Seven patients rebled. 2 patients developed bowel ischemia. Four patients underwent surgery for bowel ischemia or rebleeding. Conclusion. The use of therapeutic transcatheter embolization for treatment of acute gastrointestinal hemorrhage is highly successful and relatively safe with 98% technical success and 2.4% postembolization ischemia in our series. In 89% of cases it was definitive without any further intervention.

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.

Embolization with Histoacryl Glue of an Anastomotic Pseudoaneurysm following Surgical Repair of Abdominal Aortic Aneurysm.

We report a 62-year-old female who had surgical repair of abdominal aortic aneurysm with a bifurcated graft 2 years ago. She presented with a distal anastomotic pseudoaneurysm which was successfully embolized with histoacryl glue. Only one such similar case has been reported in the literature so far (Yamagami et al. (2006)).

An institutional review of transarterial embolization in haemorrhagic urological emergencies.

OBJECTIVE: To review the effectiveness of therapeutic transarterial embolization in controlling phagic urological emergencies irrespective of the cause of emergencies. METHODS: Thirty-seven vascular angiographies were performed in 32 patients (19 males and 13 females, age range 19-70 years) who were referred with haemorrhagic urological emergencies to Aga Khan University Hospital's angiography suite from July 2005 to June 2010. Embolization was performed with coils, polyvinyl alcohol particles, N-Butyl cyanoacrylate glue and gel foam according to the clinical indication. Data on clinical indication, technique, site and type of bleeding lesions were obtained from a retrospective review of medical records. Success rate, clinical outcome and complications of the procedure were analysed. RESULTS: Indications of procedure included iatrogenic injury (16), Renal mass on clinical examination and imaging (4), haematuria with pseudoaneurysm on examination (3), haematuria with no known cause (3), post traumatic renovascular injury (2) Renal arteriovenous fistulas (2), Carcinoma of prostate (1) and pelvic arteriovenous (AV) fistula (1). Twenty four patients underwent successful endovascular control of bleeding. Eight examinations were negative for active extravasation, two of whom showed haemorrhage in second session and were embolized. Two sessions were needed in two patients at different time intervals. Complication as dislodgement of coil in distal profunda femoris artery was seen in one patient with no significant obstruction to flow. CONCLUSION: Transarterial renal angioembolisation is a safe and effective therapeutic tool for managing haematuria or haemorrhage in urological emergencies. Wherever and whenever indicated it should be the first preferred treatment modality.

Post traumatic avulsion of lumbar artery: a rare cause of retroperitoneal haemorrhage treated by glue embolization.

Lumbar arterial injury after trauma is a rare cause of significant retroperitoneal haemorrhage. Early diagnosis followed by endovascular transcatheter embolization is a very effective treatment to control bleeding in patients who do not respond to conservative management. We present a case of post traumatic avulsion of left fourth lumbar artery which was successfully treated with percutaneous transcatheter arterial embolization with glue.

Cost-effectiveness of clipping vs coiling of intracranial aneurysms after subarachnoid hemorrhage in a developing country--a prospective study.

BACKGROUND: Endovascular coil treatment is being used increasingly as an alternative to clipping for some ruptured intracranial aneurysms. The relative benefits of these 2 approaches have yet to be fully established. The aim of this study was to compare the clinical outcome, resource consumption, and cost-effectiveness of endovascular treatment vs surgical clipping in a developing country. METHODS: The study population consisted of 55 patients with aneurysmal subarachnoid hemorrhage (SAH) identified prospectively from January 2004 to June 2007. Of the 55 patients with ruptured intracranial aneurysms, 31 underwent surgical clipping, whereas 24 were treated via interventional coils. Clinical outcome at 6 months, using the modified Rankin Scale, and cost of treatment related to all aspects of the inpatient stay were evaluated in both groups. RESULTS: The average age of the patients in the endovascular group was 38 years, whereas in the surgical group, it was 45 years. Most patients (43) were found to be in grades (1 and 2). Of these patients, 18 received coils and 25 were clipped. The remaining 12 patients were of poor grades (3 and 4), of which 6 had coiling and 6 underwent clipping. Most the patients (46/55) had anterior circulation aneurysms, and the rest of the patients (9/55) had posterior circulation aneurysms. The clinical outcome was similar in comparison (good in 81% for clipping and 83% for coiling). The average total cost for patients undergoing endovascular treatment of the aneurysms was $5080, whereas the average total cost of surgical clipping was $3127. CONCLUSION: Patients with aneurysmal SAH whom we judged to require coiling had higher charges than patients who could be treated by clipping. The benefits of apparent decrease in length of stay in the endovascular group were offset by higher procedure price and cost of consumables. There was no significant difference in clinical outcome at 6 months. We have proposed a risk scoring system to give guidelines regarding the choice of treatment considering size of aneurysm and resource allocation.

Median survival time of patients after transcatheter chemo-embolization for hepatocellular carcinoma.

OBJECTIVE: To determine the effect on survival after transarterial chemoembolization (TACE) in patients with unresectable hepatocellular carcinoma (HCC). DESIGN: Longitudinal cohort study. PLACE AND DURATION OF STUDY: Radiology Department, The Aga Khan University Hospital, Stadium Road, Karachi, from December 1997 to September 2005. PATIENTS AND METHODS: Patients undergoing TACE procedure for HCC were prospectively followed. Fortythree patients were enrolled from December 1997 to March 2003 in the study and subjected to chemoembolization therapy. Eight out of 43 patients were excluded from the study, who lost to follow-up. All the patients were followed till their death. Median and mean survival were calculated. RESULTS: The median survival of these 35 patients was 410 days (13.6 months), with 95% confidence interval (236 days lower bound and 536 days upper bound). Mean survival time was 603 days (20.1 months) with 95% confidence interval (394 days lower bound and 812 days upper bound). There was significant difference in mean survival time (in days) by Child s Pugh class (chi(2) = 12.384; df=2, p-value=0.002). CONCLUSION: The study showed that TACE is an effective palliative treatment. TACE increases the median survival time.

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.

Endovascular-covered stent treatment of posttraumatic cervical carotid artery pseudoaneurysms.

Pseudoaneurysm involving the cervical portion of the carotid artery can result from prior trauma or dissection. Two patients are reported with posttraumatic carotid artery pseudoaneurysms. In both cases, endovascular-covered stents were placed across the diseased portion of the artery resulting in thrombosis of the aneurysm and preservation of the parent artery without any significant complication. It is therefore concluded that covered stent placement is an alternative approach in treating carotid artery pseudoaneurysms.