Untangling product selectivity on clean low index rutile TiO2 surfaces using first-principles calculations.

Computational modeling of metal oxide surfaces provides an important tool to help untangle complex spectroscopy and measured catalytic reactivity. There are many material properties that make rational catalytic design challenging, and computational methods provide a way to evaluate possible structural factors, like surface structure, individually. The mechanism of water oxidation or oxygen evolution is well studied on some anatase surfaces and the rutile TiO2 (110) surface but has not yet been mapped on other low-index Miller rutile surfaces that are present in most experimental nano-titania catalysts. Here first principles calculations provide new insights into water oxidation mechanisms and reactivity of the most common low-index Miller facets of rutile TiO2. The reactivity of three surfaces, (101), (010), and (001), are explored for the first time and the product selectivity of multistep electron transfer on each surface is compared to the well-studied (110) surface. Density functional theory shows that a peroxo, O(p), intermediate is more favorable for water oxidation on all facets. The ˙OH radical formation is favored on the (001) facet resulting in a high overpotential for oxygen evolution reaction (OER). The (101) and (110) facets have low overpotentials, ∼0.3 V, and favor two-electron proton-coupled electron transfer to produce H2O2. The only facet that prefers direct OER is (001), leading to O2 evolution in a four-electron process with an overpotential of 0.53 V. A volcano plot predicts the selectivity and activity of low-index Miller facets of rutile TiO2, revealing the high activity of the peroxo OER mechanism on the (010) facet.

On a high photocatalytic activity of high-noble alloys Au-Ag/TiO2 catalysts during oxygen evolution reaction of water oxidation.

The analysis via density functional theory was employed to understand high photocatalytic activity found on the Au-Ag high-noble alloys catalysts supported on rutile TiO2 during the oxygen evolution of water oxidation reaction (OER). It was indicated that the most thermodynamically stable location of the Au-Ag bimetal-support interface is the bridging row oxygen vacancy site. On the active region of the Au-Ag catalyst, the Au site is the most active for OER catalyzing the reaction with an overpotential of 0.60 V. Whereas the photocatalytic activity of other active sites follows the trend of Au > Ag > Ti. This finding evident from the projected density of states revealed the formation of the trap state that reduces the band gap of the catalyst promoting activity. In addition, the Bader charge analysis revealed the electron relocation from Ag to Au to be the reason behind the activity of the bimetallic that exceeds its monometallic counterparts.

The Efficacy Of Azithromycin Plus Levamisole Vs Azithromycin Alone In The Treatment Of Moderate To Severe Acne.

BACKGROUND: Acne vulgaris (AV) is an inflammatory disorder of pilosebaceous unit and it affects over 85% of teenagers (peak age 17 years) during some point in their lives. Of these 30% have acne severe enough to require medical treatment. The overall incidence is comparable in both genders. Objective was to compare the efficacy of azithromycin plus levamisole with azithromycin alone in the treatment of moderate to severe acne. It was a single centre randomized controlled trial, conducted at the Department of Dermatology at Military Hospital Rawalpindi. METHODS: We selected 118 patients of acne who fulfilled the inclusion criteria from the dermatology outpatient department. Diagnosis was based on clinical features of acne and severity defined using Acne Global Severity Score. The patients were randomly assigned two treatment groups; Patients in group A received Azithromycin 500 mg per day given for 3 days a week plus oral levamisole 150 mg per day was given for 2 days a week for a total of 08 weeks. Group B patients (n= 59) received Azithromycin 500 mg per day given for 3 days a week for a total of 08 weeks. Patients were followed up fortnightly till they completed their treatment. Response to treatment was graded according to the Acne Global Severity Score. Scoring was done at first visit before therapy and after 08 weeks of therapy in both groups. Therapy was considered efficacious if the patients achieved post-therapy reduction of global score below 19 at the end of 8th week of initiation of therapy. RESULTS: Among our 118 study cases, we had 38 male patients while 80 were female patients. The study cases had mean age of 20.10±2.65 years. Mean global severity was 31.25±3.41 while 56 (47.5%) had moderate acne and 62 (52.5%) had severe acne. Efficacy was found to be higher in patients receiving Azithromycin plus levamisole combination. CONCLUSIONS: Azithromycin plus levamisole was observed as a more effective therapy for the treatment of acne as compared to Azithromycin alone. The study supports the administration of combination therapy for the treatment of Acne to achieve desired outcomes in patients.

Regulation of Ferroelectric Polarization to Achieve Efficient Charge Separation and Transfer in Particulate RuO2 /BiFeO3 for High Photocatalytic Water Oxidation Activity.

Exploiting spontaneous polarization of ferroelectric materials to achieve high charge separation efficiency is an intriguing but challenging research topic in solar energy conversion. This work shows that loading high work function RuO2 cocatalyst on BiFeO3 (BFO) nanoparticles enhances the intrinsic ferroelectric polarization by efficient screening of charges to RuO2 via RuO2 /BFO heterojunction. This leads to enhancement of the surface photovoltage of RuO2 /BFO single nanoparticles nearly 3 times, the driving force for charge separation and transfer in photocatalytic reactions. Consequently, efficient photocatalytic water oxidation is achieved with quantum efficiency as high as 5.36 % at 560 nm, the highest activity reported so far for ferroelectric materials. This work demonstrates that, unlike low photocurrent density in film-based ferroelectric devices, high photocatalytic activity could be achieved by regulating the ferroelectric spontaneous polarization using appropriate cocatalyst to enhance driving force for efficient separation and transfer of photogenerated charges in particulate ferroelectric semiconductor materials.

Treatment of displaced intracapsular fractures of the femoral neck with total hip arthroplasty or hemiarthroplasty.

AIMS: Despite few good-quality studies on the subject, total hip arthroplasty (THA) is increasingly being performed for displaced intracapsular fractures of the neck of femur. We compared outcomes of all patients with displacement of these fractures treated surgically over a ten-year period in one institution. METHODS: A total of 2,721 patients with intracapsular fractures of the femoral neck treated with either a cemented hemiarthroplasty or a THA at a single centre were retrospectively reviewed. The primary outcomes analyzed were readmission for any reason and revision surgery. We secondarily looked at mortality rates. RESULTS: We found no difference in the overall revision rate or rate of infection. However, the rates of readmission due to dislocation, pain, and trochanteric bursitis were significantly higher in the THA group (p = 0.001, p < 0.001, p < 0.001, and p = 0.001, respectively). CONCLUSION: Our study, comparing the outcomes of neck of femur fractures treated with a cemented hemiarthroplasty and THA, revealed the perceived superiority of THA was not borne out by our results. This should be carefully considered before any radical change in practice regarding the use of THA for displaced intracapsular fractures of the femoral neck. Cite this article: Bone Joint J 2020;102-B(6):693-698.

Sr2NiWO6 Double Perovskite Oxide as a Novel Visible-Light-Responsive Water Oxidation Photocatalyst.

Screening of stable visible-light-responsive water oxidation semiconductor photocatalysts is highly desired for the development of photocatalytic water splitting systems. Herein, a visible-light-absorbing Sr2NiWO6 double perovskite oxide photocatalyst was successfully prepared via a conventional solid-state reaction method. The intrinsic Sr2NiWO6 shows photocatalytic oxygen evaluation reaction (OER) activity of 60 µmol h-1 g-1, even without loading any cocatalysts. The DFT calculation indicates that the Ni species on the surface is the active site for the OER. The photocatalytic OER activity was further improved by loading Pt and RuO2 dual redox cocatalysts on the surface of Sr2NiWO6 to achieve a photocatalytic OER activity of 420 µmol h-1 g-1, which corresponds to a remarkable apparent quantum efficiency (AQE) of 8.6% (λ ≈ 420 nm). The result indicates that Sr2NiWO6 is one of the best double perovskite oxide-based photocatalysts for the photocatalytic OER, and the activity is even comparable to the benchmark BiVO4-based photocatalyst. The improvement of the photocatalytic OER activity is due to the provision of more active redox sites as well as the synergetic effect of the dual redox cocatalysts in facilitating charge separation and transfer. This work demonstrates that double perovskite oxides may serve as a novel class of efficient and stable oxide-based semiconductor photocatalysts for water splitting.

Chiral AuI - and AuIII -Isothiourea Complexes: Synthesis, Characterization and Application.

During an investigation into the potential union of Lewis basic isothiourea organocatalysis and gold catalysis, the formation of gold-isothiourea complexes was observed. These novel gold complexes were formed in high yield and were found to be air- and moisture stable. A series of neutral and cationic chiral gold(I) and gold(III) complexes bearing enantiopure isothiourea ligands was therefore synthesized and fully characterized. The steric and electronic properties of the isothiourea ligands was assessed through calculation of their percent buried volume and the synthesis and analysis of novel iridium(I)-isothiourea carbonyl complexes. The novel gold(I)- and gold(III)-isothiourea complexes have been applied in preliminary catalytic and biological studies, and display promising preliminary levels of catalytic activity and potency towards cancerous cell lines and clinically relevant enzymes.

Surgically treated rectal cancer patients--outcomes at a tertiary care cancer hospital in Pakistan.

AIM: The aim of this study was to analyze our experience with rectal cancer patients who underwent surgical excision at our institution. METHODS: Data on 112 rectal cancer patients who underwent surgical resection with total mesorectal excision, from January 2005 to December 2008, were evaluated retrospectively. RESULTS: We achieved an initial complete remission rate of 74.1%. Overall, 92.8% of patients had a complete total mesorectal excision. The overall survival analysis for all patients showed a 1-year survival rate of 98%, a 3-year survival rate of 82%, and a 5-year survival rate of 70%. We report a 41.9% rate of postoperative complications. The 1-, 3-, and 5-year survival rates for females were 100%, 90%, and 72%, respectively and for males, they were 90%, 80%, and 68%, respectively. Differences in overall survival by sex were not statistically significant (p > 0.05). Those patients who were treated with only surgery had the best outcomes with survival being worse in those treated with surgery and adjuvant therapy. Neoadjuvant treatment followed by surgery led to better results. CONCLUSION: We conclude that we have been successful in achieving high rates of curative resection, complete remission, and overall survival. Neoadjuvant and adjuvant chemotherapy significantly impact rates of remission.

Endoscopic ultrasound - fine needle aspiration of 2-deoxy-2-[18F] fluoro-D-glucose avid lymph nodes seen on positron emission tomography- computed tomography -what looks like cancer may not always be so.

BACKGROUND: Patients suffering from malignancies often undergo serial positron emission tomography - computed tomography (PET-CT) scans, using 2-deoxy-2-[18F] fluoro-D-glucose (FDG) for diagnosis and follow up. This principle may also be applied to benign conditions as inflammatory cells take up increased amounts of FDG as well. The aim of our study was to retrospectively review the cytological diagnoses made at EUS-FNA of FDG-avid PET-CT lesions in patients with a history of cancer and to determine whether the cause of FDG-avidity was neoplastic or benign. METHODS: We used the endoscopy database to extract clinical information on all patients with malignancies who underwent EUS-FNA to obtain tissue from FDG-avid nodes seen on PET-CT at our institution from 2009 - 2012. All patients who were referred for EUS-FNA after their scans were included. Those who had contraindications to endoscopic procedures were excluded. RESULTS: The most common location of positive lymph nodes was the subcarinal region (46%). A definitive diagnosis was obtained in 87.8% cases, of which 51.2% had a diagnosis of malignancy confirmed on cytology, while 36.5% were benign. Out of these, 29% had granulomatous inflammation. In 12.2% of cases no definitive diagnosis was obtained. CONCLUSION: Our results show that great caution should be exercised when evaluating FDG-avid PET-CT nodes in patients with known malignant disease, as a significant proportion of these lesions may be benign, particularly in geographic locations with a high background prevalence of granulomatous inflammation.

Primary pseudoaneurysm of the descending aorta.

Aortoesophageal fistula (AEF) is an atypical cause of massive hematemesis proving to be lethal if left untreated. We report a case of a 56-year-old man who presented with chest pain and hematemesis. He was diagnosed with pseudoaneurysm of the descending aorta and underwent open surgery for primary repair.

Adherence to the European Society of Cardiology (ESC) guidelines for chronic heart failure--a national survey of the cardiologists in Pakistan.

BACKGROUND: The aims of this study were to evaluate the awareness of and attitudes towards the 2005 European Society of Cardiology (ESC) guidelines for Heart Failure (HF) of the cardiologists in Pakistan and assess barriers to adherence to guidelines. METHODS: A cross-sectional survey was conducted in person from March to July 2009 to all cardiologists practicing in 4 major cities in Pakistan (Karachi, Lahore, Quetta and Peshawar). A validated, semi-structured questionnaire assessing ESC 2005 Guidelines for HF was used to obtain information from cardiologists. It included questions about awareness and relevance of HF guidelines (See Additional File 1). Respondents' management choices were compared with those of an expert panel based on the guidelines for three fictitious patient cases. Cardiologists were also asked about major barriers to adherence to guidelines. RESULTS: A total of 372 cardiologists were approached; 305 consented to participate (overall response rate, 82.0%). The survey showed a very high awareness of CHF guidelines; 97.4% aware of any guideline. About 13.8% considered ESC guidelines as relevant or very relevant for guiding treatment decisions while 92.8% chose AHA guidelines in relevance. 87.2% of respondents perceived that they adhered to the HF guidelines. For the patient cases, the proportions of respondents who made recommendations that completely matched those of the guidelines were 7% (Scenario 1), 0% (Scenario 2) and 20% (Scenario 3). Respondents considered patient compliance (59%) and cost/health economics (50%) as major barriers to guideline implementation. CONCLUSION: We found important self reported departures from recommended HF management guidelines among cardiologists of Pakistan.