Indirect to direct band gap transition through order to disorder transformation of Cs2AgBiBr6 via creating antisite defects for optoelectronic and photovoltaic applications

Non-toxic lead free inorganic metal halide cubic double perovskites have drawn a lot of attention for their commercial use in optoelectronic and photovoltaic devices. Here we have explored the structural, electronic, optical and mechanical properties of lead-free non-toxic inorganic metallic halide cubic double perovskite Cs₂AgBiBr₆ in its ordered and disordered forms using first-principles density functional theory (DFT) to verify the suitability of its photovoltaic and optoelectronic applications. The indirect bandgap of Cs₂AgBiBr₆ is tuned to a direct bandgap by changing it from an ordered to disordered system following the disordering of Ag⁺/Bi³⁺ cations by creating antisite defects in its sublattice. In the disordered Cs₂AgBiBr₆, the Bi 6p orbital modifies the conduction band significantly and leads to a shift the conduction band minimum (CBM) from L to Γ-point. Consequently, the system changes from indirect to direct band gap material. At the same time the band gap reduces significantly. The band gap of Cs₂AgBiBr₆ decreases from 2.04 eV to 1.59 eV. The absorption edge towards the lower energy region and strong optical absorption in the visible to the UV region indicate that the disordered direct band gap material Cs₂AgBiBr₆ is appropriate for use in solar cells and optoelectronic and energy harvesting devices. Dielectric function, reflectivity and refractive index of disordered direct band gap material Cs₂AgBiBr₆ is favorable for its optoelectronic and photovoltaic applications. However, its stability and ductility favor its thin film fabrication. The creation of antisite defects in the sublattice of double perovskites opens a new avenue for the design of photovoltaic and optoelectronic materials.

The bandgap of Cs₂AgBiBr₆ is tuned to a direct bandgap by the disordering of Ag⁺/Bi³⁺ cations, creating antisite defects. The creation of antisite defects in the sublattice of double perovskites opens a new avenue for the design of photovoltaic and optoelectronic materials.

Insights into the physical properties and anisotropic nature of ErPdBi with an appearance of low minimum thermal conductivity

We theoretically study the structural, elastic and optical properties of ErPdBi together with its anisotropic behaviors using density functional theory. It is observed that ErPdBi satisfies the Born stability criteria nicely and possesses high quality of machinability. The anisotropic behavior of ErPdBi is reported with the help of theoretical anisotropy indices incorporating 3D graphical presentation, which suggests that ErPdBi is highly anisotropic in nature. It is noticed that the minimum thermal conductivity is very low for ErPdBi compared to the several species. This low value of minimum thermal conductivity introduces the potentiality of ErPdBi in high-temperature applications such as thermal barrier coatings. In addition, deep optical insights of ErPdBi reveal that our material can be used in different optoelectronic and electronic device applications ranging from organic light-emitting diodes, solar panel efficiency, waveguides etc. to integration of integrated circuits. Therefore, we believe that our results will provide a new insight into high-temperature applications and will benefit for the development of promising optoelectric devices as well.

Chemically stable new MAX phase V2SnC: a damage and radiation tolerant TBC material

Using density functional theory, the phase stability and physical properties, including structural, electronic, mechanical, thermal and vibrational with defect processes, of a newly synthesized 211 MAX phase V₂SnC are investigated for the first time. The obtained results are compared with those found in the literature for other existing M₂SnC (M = Ti, Zr, Hf, Nb, and Lu) phases. The formation of V₂SnC is exothermic and this compound is intrinsically stable in agreement with the experiment. V₂SnC has potential to be etched into 2D MXene. The new phase V₂SnC and existing phase Nb₂SnC are damage tolerant. V₂SnC is elastically more anisotropic than Ti₂SnC and less than the other M₂SnC phases. The electronic band structure and Fermi surface of V₂SnC indicate the possibility of occurrence of its superconductivity. V₂SnC is expected to be a promising TBC material like Lu₂SnC. The radiation tolerance in V₂SnC is better than that in Lu₂SnC.

Using density functional theory, the phase stability and physical properties, including structural, electronic, mechanical, thermal and vibrational with defect processes, of a newly synthesized 211 MAX phase V₂SnC are investigated for the first time.

Pharmacokinetic Parameters Determination and In Vitro-In Vivo Correlation of Ileocolonic-Targeted pH-Responsive Coated Mini-Tablets of Naproxen

This research work aims to determine the pharmacokinetic parameters and in vitro-in vivo correlation of the selected ileocolonic-targeted coated mini-tablet filled capsule formulation of naproxen. The pure suspension and coated mini-tablet filled capsule formulation of naproxen were administered to adult albino rabbits through the oral route. The samples were analyzed for naproxen by an HPLC method. For the pure drug suspension, the peak plasma concentration was found as 8.499±0.029 μg/ml at 1.139±0.010 hours and the half-life was found to be 9.459±0.387 hours, whereas for the formulation the peak plasma concentration was found as 6.814±0.037 μg/ml at 8.042±0.069 hours and the half-life was found to be 19.657±0.359 hours. This decreased the peak plasma concentration at a delayed time and increased the half-life of the capsule formulation in comparison with the pure drug suspension which showed that naproxen was only targeted to the ileocolonic region. A significant in vitro-in vivo correlation (i.e. R(2)=0.9901) was also obtained. Thus, the results of these findings suggest that naproxen formulated as coated mini-tablets can be suitable for targeted ileocolonic drug delivery.

Formulation and evaluation of ileo-colonic targeted matrix-mini-tablets of Naproxen for chronotherapeutic treatment of rheumatoid arthritis

In this present research work, the aim was to develop ileo-colonic targeted matrix-mini-tablets-filled capsule system of Naproxen for chronotherapeutic treatment of Rheumatoid Arthritis. So Matrix-mini-tablets of Naproxen were prepared using microsomal enzyme dependent and pH-sensitive polymers by direct compression method which were further filled into an empty HPMC capsule. The compatibility was assessed using FT-IR and DSC studies for pure drug, polymers and their physical mixtures. The prepared batches were subjected to physicochemical studies, drug content estimation, in-vitro drug release and stability studies. When FTIR and DSC studies were performed, it was found that there was no interaction between Naproxen and polymers used. The physicochemical properties of all the prepared matrix-mini-tablets batches were found to be in limits. The drug content percentage in the optimized formulation F18 was found to be 99.24 ± 0.10%. Our optimized matrix-mini-tablets-filled-capsule formulation F18 releases Naproxen after a lag time of 2.45 ± 0.97 h and 27.30 ± 0.86%, 92.59 ± 0.47%, 99.38 ± 0.69% at the end of 5, 8, 12 h respectively. This formulation was also found to be stable as per the guidelines of International Conference on Harmonisation of Technical Requirements of Pharmaceuticals for Human Use. Thus, a novel ileo-colonic targeted delivery system of Naproxen was successfully developed by filling matrix-mini-tablets into an empty HPMC capsule shell for targeting early morning peak symptoms of rheumatoid arthritis.

Formulation and evaluation of mini-tablets-filled-pulsincap delivery of lornoxicam in the chronotherapeutic treatment of rheumatoid arthritis

In this present research work, we have designed a pulsincap formulation comprising mini-tablets, which to the best of our knowledge this combination has not been reported yet. We successfully combined the advantages of mini-tablets technology to meet the optimized requirements of our pulsincap formulation. Our main aim was to target lornoxicam to treat rheumatoid arthritis as per the chronotherapeutic pattern of the disease. Directly compressing method was used to prepare mini-tablets. The drug, polymers and combine mixtures of drug and polymers was evaluated for pre-formulation testing. Prepared mini-tablets were also evaluated for physicochemical, dissolution and stability studies. From FTIR and DSC evaluation, we found no interaction between the drug and polymers used. For mini-tablets, all the physico-chemical parameters were in limit. The mini-tablets of lornoxicam were filled into an insoluble body of capsule, and its opening was sealed by plugging it with a polymer. The complete capsule body after sealing with a cap was given enteric coating. Different polymers in various concentrations were used as a plug, to identify the most suitable which gives a complete lag time of 5 hours when combined with 5% CAP coating. HPMC-K100M in 30% and sodium alginate in 40% concentrations were identified as the most suitable plugs. Our optimized pulsincap formulations releases lornoxicam after a lag time of 5 hrs and maximum portion of the drug will be released in the early morning hours. It was also found to be stable for a period of 6 months as per ICH guidelines.

Public safety assessment of electromagnetic radiation exposure from mobile base stations

Exposure of the general public to electromagnetic radiation originating from randomly selected GSM/WCDMA base stations in Riyadh, Kingdom of Saudi Arabia has been assessed in the context of the International Commission on Non-Ionising Radiation Protection (ICNIRP) guidelines. The purpose of the measurement was to record the maximum power density of signals to estimate possible worst case exposure at each measurement location. These power density measurements were carried out at 60 mobile base stations located in different regions of the city. For each of these sites, three sectors were operational, yielding a total of 180 sectors. Two positions were identified per site with the greatest power density values. Exposures from these base stations were generally found to be in the range of 0.313 to 0.00000149% of the ICNIRP general public reference level, and the greatest exposure near any of the base stations was 21.96 mW m(-2) for a wideband measurement in the 75-3000 MHz frequency range. Analysis of the measured data reveals several trends for different mobile bands with respect to maximum exposure in those locations. Additionally, a simplified calculation method for the electromagnetic fields was used to compare calculated and the measured data. It was determined, on the basis of both results of the measurements and calculations carried out for these selected base stations, that members of the public would not be exposed to in excess of a small fraction of the ICNIRP guidelines at any of those sites. These are first such measurements to be made in the Middle East and provide assurance that exposures in this region of the world do not seem to be any greater than elsewhere.

A comparative study of intravenous patient-controlled analgesia morphine and tramadol in patients undergoing major operation

The success of major surgery depends partly on providing effective post-operative pain relief, which can be commonly achieved by morphine administration via patient- controlled analgesic (PCA) system. Alternatively, tramadol which is a weak opioid analgesic, can be used for post operative pain relief. The purpose of this study was to evaluate the effectiveness of intravenous PCA tramadol in comparison with PCA morphine in term of analgesic properties, sedation and side effects. A randomized, double-blinded study was conducted on 160 ASA I and II patients who underwent major operations. Eighty of them received a loading dose of intravenous morphine 0.1 mg/kg followed by PCA morphine bolus of 1 mg (1 mg/ml) as required, while the other 80 patients received a loading dose of 2.5 mg/kg of intravenous tramadol followed by PCA infusion of 10 mg (10 mg/ml) as required. Patients were monitored for pain, sedation and side effects as well as respiratory rate, nausea, vomiting, pruritus, blood pressure and pulse rate. Patients were evaluated 30 minutes, 4 hours, 24 hours and 48 hours post operation. There were no differences in the demographic data between the two groups (p > 0.05). The overall mean pain score in tramadol group was 0.70 +/- 0.60 as compared to 0.75 +/- 0.67 for morphine group. The mean pain score for tramadol and morphine groups at 30 minutes, 4 hours, 24 hours and 48 hours post operation were 1.32 +/- 0.79, 104 +/- 0.79, 0.35 +/- 0.48, 0.09 +/- 0.33 and 1.35 +/- 0.99, 1.14 +/- 0.81, 0.40 +/- 0.54, 0.10 +/- 0.34 respectively. The overall mean sedation score in tramadol and morphine group was 0.39 +/- 0.44 as compared to 0.35 +/- 0.43 for morphine group. The mean sedation score for tramadol and morphine group at 30 minutes, 4 hours, 24 hours and 48 hours post operation were 0.90 +/- 0.74, 0.56 +/- 0.59, 0.075 +/- 0.27, 0.025 +/- 0.16 and 0.84 +/- 0.70, 0.46 +/- 0.64, 0.08 +/- 0.27, 0.01 +/- 0.11 respectively. There was no significant difference in the overall mean pain and sedation score between the two groups as well as for each duration assessed (p > 0.05). There were also no significant differences between the two groups with regard to the blood pressure and heart rate. The incidence of nausea, vomiting and pruritus were the same in the two groups. This study indicates that PCA tramadol is as equally effective as PCA morphine control following major surgery. The incidences of sedation, nausea or pruritus were the same in the two groups.

The incidentally discovered asymptomatic adrenal tuberculous mass mimicking malignancy

Tuberculous adrenal mass without any tuberculous changes in other sites is a rare entity. In this study we describe such a case. A male patient of 47 years with 6 months history of anorexia and weakness was presented. Ultrasonography and computed tomography revealed a mass in the right adrenal gland. It was mistaken as a malignant neoplasm and the diagnosis was confirmed by surgical exploration.

Spontaneous expulsion of intrabronchial metallic foreign body: a case report

Inhalation of metallic foreign bodies is a rare event occurring mostly in children, and often requires early surgical intervention to avoid complications. We report a case of spontaneous expectoration of an intrabronchial metallic nail in an adult, 2 hours after inhalation.

Antibiotic compared with antiseptic prophylaxis for prostatic surgery

Two different regimens of cephalosporin antibiotic prophylaxis were compared with antiseptic lubricating jelly to try to prevent infection and complications in 196 men after prostatic surgery. Pre-operative urine was cultured and prostatic chips (170 cases) were also cultured to define the source of any infection. The use of antibiotics was associated with a reduced risk of postoperative bacteriuria. No serious complications occurred, although 1 patient in the antiseptic treated group developed rigors; 79 of 170 patients (46%) had positive prostatic chip cultures, of whom 74 had sterile pre-operative urine. There was no association between the result of chip culture and the presence of a pre-operative catheter. Culture positive patients had an increased risk of post-operative urine infection, although the same organism was found in the prostate and urine in only 36% of cases of post-operative bacteriuria and in 43 (54%) the organism cultured from the prostate was Staphylococcus albus. This study provides further evidence of the benefit of true prophylactic antibiotic therapy for transurethral prostatic surgery and the prostatic chip data suggest that some of the risk is due to pre-operative contamination of the prostate in the absence of per-operative urinary infection or catheterisation.