Laser-assisted plasma formation and ablation of Cu in a controlled environment.

In this paper, we explore the surface and mechanical alterations of Cu, as well as the parameters of laser-assisted plasma and ablation. The irradiation source is a Nd: YAG laser with a constant irradiance of 1.0 GW/cm2 (1064 nm, 55 mJ, 10 ns, 10 Hz). Physical parameters such as electron temperature (Te) and electron number density (ne), sputtering yield (yield), ablation depth (depth), surface morphology (morphology), and hardness (Vickers) of laser irradiated Cu are evaluated using instruments such as a Laser Induced Breakdown Spectrometer (LIBS), Quartz Crystal Microbalance (QCM), Optical Emission Microscope (OEM), Scanning Electron Microscope (SEM), and Vicker's hardness tester. These physical characteristics have been studied in relation to changes in pressure (from 10 torr to 100 torr) and the composition of two inert ambient gases (Argon and Neon). Pressures of Ar and Ne are found to enhance the emission intensities of spectral lines of Cu, Te, and ne, as well as the sputtering yield, crater depth, and hardness of laser ablated Cu, to a maximum at 60 torr, after which they decrease with subsequent increases in pressure up to 100 torr. Increases in pressure up to 60 torr are connected with plasma confinement effects and increased collisional frequency, whereas decreases in pressure between 60 and 100 torr are ascribed to shielding effects by the plasma plume. All numbers are also found to be greater in Ar compared to Ne. In Ar, laser-ablated Cu reaches a maximum of 15218 K, 1.83 × 1018 cm-3, 8.59 × 1015 atoms/pulse, 231 m, and 147 HV, whereas in Ne, it reaches a maximum of 12000 K, 1.75 × 1018 cm-3, 7.70 × 1015 atoms/pulse, 200 m, and 116 HV. Ar is more likely than Ne to develop surface features such as craters, distinct melting pools with elevating edges, flakes, cones, etc. It is also shown that there is a significant association between the outcomes, with an increase in Te and ne being responsible for a rise in sputtering yield, ablation depth, surface morphology, and surface hardness. These findings have potential uses in plasma spectroscopy for materials science and in industrial applications of Cu.

Enhancing catalytic activity of gold nanoparticles in a standard redox reaction by investigating the impact of AuNPs size, temperature and reductant concentrations.

In this work, the catalytic activity of three different sizes of gold nano particles (AuNPs) (12, 30, and 45 nm) synthesized by the citrate reduction process studied in the conventional redox reaction of K3Fe (CN6)-3 to K4Fe (CN6)-4 using NaBH4(reductant) at four different temperatures (5 °C, 10 °C, 15 °C, and 20 °C) and measured by UV-visible spectrophotometry. Comparative kinetic analysis of different sizes of AuNPs including rate constant, activation energy, Entropy values and Frequency of collisions are reported for the first time. Transmission electron microscopy analysis is employed to investigate morphology and particle size. Spherical nanoparticles of size 12, 30, and 45 nm were observed. The UV-visible spectra were recorded at regular intervals, and it was seen that the peak of K3Fe (CN6)-3 decreased gradually with time, at the same time surface plasmon resonance of AuNPs remained constant. As reaction catalysts, AuNPs maintain their optical density which shows their stability during the course of reaction. The kinetic parameters i.e., rate constant, and activation energy (k, t1/2, Ea) were determined for three distinct sizes of gold nanoparticles (AuNPs) using the reductant at various concentrations. The value of k increases by increasing reductant concentration. This rise was significant for the small AuNPs. Increasing gold nanoparticle size (12, 30, 45 nm) decreased rate constant. As the size of AuNPs decreased the Ea reduced as well, i.e. 17.325 k cal mol-1 for 12 nm, 19 k cal mol-1 for 30 nm and 21 k cal mol-1 for 45 nm AuNPs. For 50 mM of NaBH4, k for 45 nm AuNPs is 0.10728 s-1, but for 12 nm AuNPs, the value of k is 0.145 s-1, indicating that the 12 nm AuNPs have the greatest rate constant values. The rate of reaction rises with an increase in reductant concentration and temperature, but this increase is significant in the case of small-sized nanoparticles, i.e., 12 nm, which have a high surface area and low Ea. Besides being a model redox reaction, the reduction of K3Fe (CN6)-3 to K4Fe (CN6)-4 has industrial use in making fertilizers and paint industry, anti-coating agent in colour photography, in dot etching and in amperometric biosensors.

Fabrication of Efficient and Non-Enzymatic Electrochemical Sensors for the Detection of Sucrose.

Molecularly imprinted polymers have been used for the creation of an electrochemical sensor for the detection of sucrose, which are modified by using functionalized graphene (fG). Using AIBN as the free radical initiator and sucrose as the template, imprinted polymers are synthesized. The monomer, 4,4'-diisocyanatodiphenylmethane (DPDI), has both proton donor groups (N-H or O-H) and lone-pair donor groups (C=O). By creating H-bonds with electron donor groups (C=O), the proton donor group in this polymer may interact with the sugar molecule serving as its template. The sensor signals have improved as a result of the interaction between the monomer and the template. Thermogravimetric and differential thermal analysis (TGA/DTA) curves, scanning electron microscopy (SEM), and FT-IR spectroscopy have been employed to characterize the fabricated receptors. The fabricated sensor has exhibited a limit of detection of 16 ppb for the target analyte that is highly sensitive, linear, reversible, regenerative, and selective. Moreover, the sensor's stability, reproducibility, and reusability have been evaluated for six months, following the device's manufacturing, and the results revealed similar responses with the percentage error of less than 1%. Most importantly, this sensor has demonstrated a quick response time, which is very sensitive, stable, and selective.

Efficient Approximate Kernel Based Spike Sequence Classification.

Machine learning (ML) models, such as SVM, for tasks like classification and clustering of sequences, require a definition of distance/similarity between pairs of sequences. Several methods have been proposed to compute the similarity between sequences, such as the exact approach that counts the number of matches between k-mers (sub-sequences of length k) and an approximate approach that estimates pairwise similarity scores. Although exact methods yield better classification performance, they pose high computational costs, limiting their applicability to a small number of sequences. The approximate algorithms are proven to be more scalable and perform comparably to (sometimes better than) the exact methods - they are designed in a "general" way to deal with different types of sequences (e.g., music, protein, etc.). Although general applicability is a desired property of an algorithm, it is not the case in all scenarios. For example, in the current COVID-19 (coronavirus) pandemic, there is a need for an approach that can deal specifically with the coronavirus. To this end, we propose a series of ways to improve the performance of the approximate kernel (using minimizers and information gain) in order to enhance its predictive performance pm coronavirus sequences. More specifically, we improve the quality of the approximate kernel using domain knowledge (computed using information gain) and efficient preprocessing (using minimizers computation) to classify coronavirus spike protein sequences corresponding to different variants (e.g., Alpha, Beta, Gamma). We report results using different classification and clustering algorithms and evaluate their performance using multiple evaluation metrics. Using two datasets, we show that our proposed method helps improve the kernel's performance compared to the baseline and state-of-the-art approaches in the healthcare domain.

Application of Rikkli and Regazzoni three-column theory in distal radius intraarticular fractures and its functional and radiological assessment.

Objectives: To determent the effectiveness of Rikli and Regazzoni three-column theory in treating intra-articular fractures of the distal radius with T-plate and K-wire in terms of functional outcome and fracture union. METHODS: The cross-sectional study was conducted at the Department of Orthopaedic Surgery and Traumatology, King Edward University, Mayo Hospital, Lahore, Pakistan, from June 2013 to March 2017, and comprised patients aged 15-60 years having closed intraarticular fracture of the distal radius <1 month older. The subjects were divided into two group A, managed by percutaneous K-wire fixation, and group B, managed with open reduction and internal fixation using T-plates. Wound infection, supination and pronation, flexion and extension at the wrist joint, bone union and functionality were observed. All patients were followed up with intervals for 12 months in the out-patient department, and wound infection and supination and pronation of the forearm were observed clinically. Union was observed using the standard criterion, and function was evaluated using the Disabilities of Arm, Shoulder and Hand score. Data was analysed using SPSS 20. RESULTS: Of the 60 patients, there were 30(50%) with mean age 48.83±11.11 years in group A, and 30(50%) with mean age 49.87±13.45 years in group B. Overall, there were 49(81.7%) males and 11(18.3%) females. There were 33(55%) cases with right side involvement, and 27(45%) had the left side involved. Functionality imprived significantly in both groups (p<0.05). Union was observed in all cases in both groups, while the mean duration in group A was 9.21±1.74 weeks, and in group B it was 9.87±2.14 weeks. Conclusion: Restoration of the three columns of distal radius could either be fixed with T-plates and K-wires because there was no significant difference between the two groups.

Predictors and 3-year outcomes of compromised left circumflex coronary artery after left main crossover stenting.

BACKGROUND: There are few predictors of decreased fractional flow reserve (FFR) in the left circumflex coronary artery (LCx) after left main (LM) crossover stenting. OBJECTIVES: We aimed to determine the predictors for low FFR at LCx and possible treatment strategies for compromised LCx, together with their long-term outcomes. METHODS: Altogether, 563 patients who met the inclusion criteria were admitted to our hospital from February 2015 to November 2020 with significant distal LM bifurcation lesions. They underwent single-stent crossover percutaneous coronary intervention (PCI) under intravascular ultrasound (IVUS) guidance with further LCx intervention based on the measured FFR. RESULTS: The patients showed significant angiographic LCx ostial affection post-LM stenting, but only 116 (20.6%) patients had FFR < 0.8. The three-year composite major adverse cardiac events (MACE) rates were comparable between the high and low FFR groups (16.8% vs. 15.5; p = 0.744). In a multivariate analysis, low FFR at the LCx was associated with post-stenting minimal luminal area (MLA) of LCx (odds ratio [OR]: 0.032, p < .001), post-stenting LCx plaque burden (OR: 1.166, p < .001), poststenting LM MLA (OR: 0.821, p = .038), and prestenting LCx MLA (OR: 0.371, p = .044). In the low FFR group, those with compromised LCx managed with drug-eluting balloon had the lowest three-year MACE rate (8.1%), as compared to either those undergoing kissing balloon inflation (KBI) (17.5%) or stenting (20.5%) (p = 0.299). CONCLUSION: Unnecessary LCx interventions can be avoided with FFR-guided LCx intervention. Poststenting MLA and plaque burden of the LCx, and main vessel stent length are poststenting predictors of low FFR.

Fabrication and performance evaluation of polymeric membrane using blood compatible hydroxyapatite for artificial kidney application.

In the current study, a phase inversion scheme was employed to fabricate hydroxyapatite (HA)/polysulfone (PSF)-based asymmetric membranes using a film applicator with water as a solvent and nonsolvent exchanging medium. Fourier Transform Infrared (FTIR) and X-ray diffraction (XRD) spectroscopic studies were conducted to confirm the bonding chemistry and purity of filler. The inherent thick nature of PSF generated sponge-like shape while the instantaneous demixing process produced finger-like pore networks in HA/PSF-based asymmetric membranes as exhibited by scanning electron microscope (SEM) micrographs. The FTIR spectra confirmed noncovalent weak attractions toward the polymer surface. The leaching ratio was evaluated to observe the dispersion behavior of HA filler in membrane composition. Hydrophilicity, pore profile, pure water permeation (PWP) flux, and molecular weight cutoff (MWCO) values of all formulated membranes were also calculated. Antifouling results revealed that HA modified PSF membranes exhibited 43% less adhesion of bovine serum albumin (BSA) together with >86% recovery of flux. Membrane composition showed 74% total resistance, out of which 60% was reversible resistance. Biocompatibility evaluation revealed that the modified membranes exhibited prothrombin time (PT), and thrombin time (TT) comparable with typical blood plasma, whereas proliferation of living cells over membrane surface proved its nontoxic behavior toward biomedical application. The urea and creatinine showed effective adsorption aptitude toward HA loaded PSF membranes.

Machine learning in primary care: potential to improve public health.

It is estimated that missed opportunities for diagnosis occur in 1 in 20 primary care appointments. This is not only detrimental to individual patients, but also to the healthcare system as health outcomes are affected and healthcare expenditure inevitably increases. There are many potential solutions to limit the number of missed opportunities for diagnosis and management, one of which is through the use of artificial intelligence. Artificial intelligence and machine learning research and capabilities have exponentially grown in the past decades, with their applications in medicine showing great promise. As such, this review aims to discuss the possible uses of machine learning in primary care to maximise the quality of care provided.

Laser-induced breakdown spectroscopy of aluminum plasma in the absence and presence of magnetic field.

The effect of magnetic field on laser-induced breakdown spectroscopy of aluminum (Al) plasma has been investigated. Al targets were exposed to Nd:YAG laser pulses at different irradiances ranging from 1 GWcm-2 to 2.7 GWcm-2, under argon (Ar) and neon (Ne) environments at various pressures ranging from 5 torr to 760 torr and at different time delays from 0.42 µs to 9.58 µs. All spectroscopy measurements were performed in the absence and presence of transverse magnetic field of strength 0.9 tesla. When laser irradiance is increased by keeping the pressure (10 torr) and time delay constant (1.25 µs), both excitation temperature (Te) and number density (ne) increase up to certain values. The same trend is observed for Te and ne when the ambient gas pressure of Ar and Ne is increased by keeping the irradiance (1.7 GWcm-2) and time delay constant. At higher irradiances and pressures, saturation is observed, which is attributed to the self-regulating regime of plasma. In the case of time delay, both electron temperature and number density decay exponentially, which is according to the adiabatic expansion model. It is revealed that emission intensity and electron temperature are higher in the presence of magnetic field as compared to the field-free case, which is attributed to magnetic confinement, as well as the joule heating effect. Plasma plume confinement is confirmed by analytical evaluation factor ß. ß is an analytical factor that is the ratio of plasma pressure to magnetic pressure, i.e., ß=Plasma pressureMagnetic pressure. It confirms the validity of magnetic field confinement if ß is less than 1. As the evaluated values of ß are less than 1 for all cases, they confirm the validity of magnetic confinement.

A novel technique to remove inferior vena cava filters using a homemade snare device.

The need to retrieve inferior vena cava filters is quite evident due to the long-term complications. We present a novel technique to remove inferior vena cava filters using a homemade snare created using a looped a 0.014-inch semistiff wire. Employing this technique, 18 consecutive retrievable filters were removed. All filters were easily snared on the very first attempt, and no complications occurred. Our novel technique to retrieve filters is efficient, safe, and cost-effective.

Perioperative risk factors for 30-day mortality after bariatric surgery: is functional status important?

BACKGROUND: Although the mortality from bariatric surgery is low, perioperative determinants of morbidity and mortality in the bariatric surgery population to date have not been fully defined. This study aimed to evaluate the factors capable of predicting perioperative mortality based on preoperative characteristics with a national patient sample. METHODS: From the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database, all the primary bariatric procedures performed between 2007 and 2009 were identified. Using univariate analysis, factors associated with increased perioperative (30-day) mortality were identified. Logistic regression was used to select correlates of 30-day mortality, which were subsequently integrated into a simplified clinical scoring system based on the number of comorbid risk factors. RESULTS: The study identified 44,408 patients (79 % women, 21 % men) with a mean age of 45 ± 11 years. The cumulative 30-day perioperative mortality rate was 0.14 %. The majority of the procedures performed included laparoscopic gastric bypass (54 %) followed by laparoscopic gastric banding (33 %) and open gastric bypass (7 %). Independent predictors associated with significantly increased mortality included age >45 years [adjusted odds ratio (AOR), 2.45], male gender (AOR = 1.77), a body mass index (BMI) of 50 kg/m(2) or higher (AOR, 2.48), open bariatric procedures (AOR, 2.34), diabetes (AOR, 2.88), functional status of total dependency before surgery (AOR, 27.6), prior coronary intervention (AOR, 2.66), dyspnea at preoperative evaluation (AOR, 4.64), more than 10 % unintentional weight loss in 6 months (AOR, 13.5), and bleeding disorder (AOR, 2.63). Ethnicity, hypertension, alcohol abuse, liver disease, and smoking had no significant association with mortality in this study. Risk stratification based on the number of preoperative comorbid factors showed an exponential increase in mortality as follows: 0-1 comorbidities (0.03 %), 2-3 comorbidities (0.16 %), and 4 comorbidities or more (7.4 %). CONCLUSION: This model provides a straightforward, precise, and easily applicable tool for identifying bariatric patients at low, intermediate, and high risk for in-hospital mortality. Notably, baseline functional status before surgery is the single most powerful predictor of perioperative survival and should be incorporated into risk stratification models.

Cancer data analysis in the pathology department, combined military hospital, Multan, Pakistan 2002-2007.

This study was conducted with the objective of providing the pattern of cancer distribution from a hospital based tumour registry at CMH, Multan, in comparison with patterns from other National Studies. The retrospective study of malignant tumours recorded at the pathology department from 2002-2007 featured analysis in terms of age group, gender and type of tumour. Over the six year period the total number of malignancies was 930 with a male to female ratio of 1.4:1. The common tumours in males, in order of decreasing frequency were leukaemia, prostate cancer, urinary bladder cancer, skin cancer and lymphomas. In females they were leukaemia, breast cancer, skin cancer, gallbladder cancer and lymphomas. In both sexes, the most common malignancy was leukaemia, which is contrary to other studies, pointing to a possible link with extensive use of pesticides and other agricultural chemicals in this region of the country.

Aneurysm of the right subclavian artery presenting as hoarseness of voice.

Intrathoracic segment of the subclavian artery is a rare location for a peripheral arterial aneurysm. A young man presented with hoarseness of voice, diminished pulses in right upper limb and superior mediastinal widening on X-ray chest. Computed tomography (CT) scan revealed an aneurysm of right subclavian artery with thrombus in its wall. Surgical repair of the aneurysm was carried out due to risk of rupture.

Current radiologic interventions in hepatocellular carcinoma.

With the rising incidence of chronic liver disease caused by viral hepatitis, hepatocellular carcinoma is showing a corresponding rise worldwide. Surgery remains the mainstay of treatment, but patients unfit for surgery or liver transplantation form the bulk of those presenting with this disease. Palliative treatments are being used to treat those and radiological modalities form the mainstay of the treatment. Radiology plays a major role in the diagnosis, treatment and follow-up of hepatocellular carcinoma. Current radiological treatment modalities include percutaneous ethanol ablation, radiofrequency ablation and trans-arterial chemoembolization. This update highlights the recent advancements in the field and compares their relative merits and demerits.