Impact of haemodialysis on plasma carnitine concentrations in haemodialysis patients.

Objective: To evaluate the impact of haemodialysis on plasma carnitine levels. METHODS: The cross-sectional study was conducted from April 20, 2020 to May 10, 2022, at the dialysis unit of the nephrology ward of Jinnah Postgraduate Medical Centre, Karachi, and the Pakistan Navy Ship Shifa Hospital, Karachi, in collaboration with the Department of Biochemistry, University of Karachi, and comprised patients of either gender aged >18 years. They were divided into chronic kidney disease group A and end-stage renal disease group B. Control group C included subjects from the general population. Free carnitine and total carnitine values were detected using enzyme-linked immunosorbent assay. Acyl carnitine was estimated by applying the standard formula, and the ratio between acyl carnitine and free carnitine was calculated for accurate assessment of the carnitine status. Data was analysed using SPSS 23. RESULTS: Of the 203 subjects, 143(70.44%) were cases and 60(29.55%) were controls. Among the cases, 120(84%) were recruited from Jinnah Postgraduate Medical Centre and 23(16%) from Pakistan Navy Ship Shifa Hospital. There were 60(29.55%) patients in group A, 83(40.88%) in group B and 60(29.55%) in group C. The mean age in group A was 47.90 5.±65 years, it was 44.10 ±8.92 years in group B and 40.90 ± 6.73 years in group C. There was a significant difference related to free carnitine, total carnitine, acyl carnitine values and the ratio between acyl carnitine and free carnitine values in groups A and B compared to control group C (p<0.05). Conclusion: Patients on maintenance haemodialysis developed were found to have developed carnitine deficiency.

Spectrum of Liver Injury in Dengue Fever: Cause or Effect of Severe Dengue?

The study aimed to determine if deranged liver function tests (LFTs) can predict severe dengue or mortality. It included 135 dengue patients, with a mean age of 30.9 ± 12.09 years. Among the patients, 82 (60.7%) were under 30 years of age. Nearly half of the patients (64, 47. 4%) had some degree of liver damage indicated by deranged LFTs, 27 (42.1%) had elevated alanine transaminase (ALT), 7 (10.9%) had increased bilirubin, and 30 (46.9%) had high values of alkaline phosphatase (ALP). However, only elevated ALP levels were positively correlated with mortality (Pearson's R = 0.282, p = <0.05). The mean bilirubin was 11.711 ± 8.602 umol/l, and the mean values of ALT and ALP were 107 ± 240 and 113.571 ± 59.91 IU/L, respectively, which were higher than the normal. The study findings suggested that hepatic derangement is a common occurrence in dengue patients, and increased ALP levels could be an indicator of a higher risk of mortality. These findings can help improve patient care by identifying the potential risk factors for mortality. Key Words: Dengue, Liver function tests, Alanine transaminase, Alkaline phosphatase.

Multi-Method Analysis of Histopathological Image for Early Diagnosis of Oral Squamous Cell Carcinoma Using Deep Learning and Hybrid Techniques.

Oral cancer is a fatal disease and ranks seventh among the most common cancers throughout the whole globe. Oral cancer is a type of cancer that usually affects the head and neck. The current gold standard for diagnosis is histopathological investigation, however, the conventional approach is time-consuming and requires professional interpretation. Therefore, early diagnosis of Oral Squamous Cell Carcinoma (OSCC) is crucial for successful therapy, reducing the risk of mortality and morbidity, while improving the patient's chances of survival. Thus, we employed several artificial intelligence techniques to aid clinicians or physicians, thereby significantly reducing the workload of pathologists. This study aimed to develop hybrid methodologies based on fused features to generate better results for early diagnosis of OSCC. This study employed three different strategies, each using five distinct models. The first strategy is transfer learning using the Xception, Inceptionv3, InceptionResNetV2, NASNetLarge, and DenseNet201 models. The second strategy involves using a pre-trained art of CNN for feature extraction coupled with a Support Vector Machine (SVM) for classification. In particular, features were extracted using various pre-trained models, namely Xception, Inceptionv3, InceptionResNetV2, NASNetLarge, and DenseNet201, and were subsequently applied to the SVM algorithm to evaluate the classification accuracy. The final strategy employs a cutting-edge hybrid feature fusion technique, utilizing an art-of-CNN model to extract the deep features of the aforementioned models. These deep features underwent dimensionality reduction through principal component analysis (PCA). Subsequently, low-dimensionality features are combined with shape, color, and texture features extracted using a gray-level co-occurrence matrix (GLCM), Histogram of Oriented Gradient (HOG), and Local Binary Pattern (LBP) methods. Hybrid feature fusion was incorporated into the SVM to enhance the classification performance. The proposed system achieved promising results for rapid diagnosis of OSCC using histological images. The accuracy, precision, sensitivity, specificity, F-1 score, and area under the curve (AUC) of the support vector machine (SVM) algorithm based on the hybrid feature fusion of DenseNet201 with GLCM, HOG, and LBP features were 97.00%, 96.77%, 90.90%, 98.92%, 93.74%, and 96.80%, respectively.

Comparison of Clinical Characteristics and Outcome of COVID-19 Patients Between the 4th and 5th Wave in a Tertiary Care Hospital in Karachi, Pakistan.

ABSTRACT       Objective: To compare the clinical parameters of 4th and 5th COVID waves in Karachi, Pakistan. STUDY DESIGN: Descriptive study. Place and Duration of the Study: PNS Shifa Hospital, Karachi, from July 2021 to February 2022. METHODOLOGY: All patients with COVID-19 in PNS Shifa Hospital were included in the study. The patients were divided into two groups, those who had COVID-19 during the 4th wave, and others who had it during the 5th wave. The patients' demographic details, comorbidities, vaccination status, initial presentation, the severity of disease, clinical progress, and final disposal from the hospital were noted. A comparison of severity, length of hospital stays, and mortality was made between the groups. RESULTS: There were 747 patients admitted during the Delta variant-dominated 4th wave of COVID-19, and 490 patients during the 5th wave, dominated by the Omicron variant. A vast majority of fifth-wave patients had the mild disease (87.35% vs. 49.39%), with significantly lower critical patients (2.04% vs. 7.09%). Vaccination was effective against both the Delta and the Omicron variant of the SARS-CoV-2 virus. The mean length of stay in the hospital for patients was significantly lesser (p < 0.001) during the 5th wave as compared to the 4th wave (6.43 ± 3.37 vs. 9.56 ± 5.45 days). The mortality rate was 7.09% among patients admitted in the 4th wave and 2.04% in the 5th wave. This difference was statistically significant (p < 0.001). CONCLUSION: The severity of disease, length of hospital stays, and mortality were higher in the Delta variant-dominated 4th wave of COVID-19 as compared to the Omicron variant-dominated 5th wave in Pakistan. The vaccination was effective against both the Delta and the Omicron variant of COVID 19, as the mortality rate among the vaccinated patients during the two waves was not significantly different. KEY WORDS: COVID 19, Vaccination, Disease outcome, Mortality.

Causal speech enhancement using dynamical-weighted loss and attention encoder-decoder recurrent neural network.

Speech enhancement (SE) reduces background noise signals in target speech and is applied at the front end in various real-world applications, including robust ASRs and real-time processing in mobile phone communications. SE systems are commonly integrated into mobile phones to increase quality and intelligibility. As a result, a low-latency system is required to operate in real-world applications. On the other hand, these systems need efficient optimization. This research focuses on the single-microphone SE operating in real-time systems with better optimization. We propose a causal data-driven model that uses attention encoder-decoder long short-term memory (LSTM) to estimate the time-frequency mask from a noisy speech in order to make a clean speech for real-time applications that need low-latency causal processing. The encoder-decoder LSTM and a causal attention mechanism are used in the proposed model. Furthermore, a dynamical-weighted (DW) loss function is proposed to improve model learning by varying the weight loss values. Experiments demonstrated that the proposed model consistently improves voice quality, intelligibility, and noise suppression. In the causal processing mode, the LSTM-based estimated suppression time-frequency mask outperforms the baseline model for unseen noise types. The proposed SE improved the STOI by 2.64% (baseline LSTM-IRM), 6.6% (LSTM-KF), 4.18% (DeepXi-KF), and 3.58% (DeepResGRU-KF). In addition, we examine word error rates (WERs) using Google's Automatic Speech Recognition (ASR). The ASR results show that error rates decreased from 46.33% (noisy signals) to 13.11% (proposed) 15.73% (LSTM), and 14.97% (LSTM-KF).

Miniaturized ultra-wideband filter with independently controlled notch bands for 5.1/6/8 GHz wireless applications.

A novel three-mode step impedance resonator (TSIR) is developed to design a miniaturized multi-pole microstrip planar ultra-wideband (UWB) filter with independently controlled notched bands at different frequencies is presented in this work. The basic UWB filter consists of four L-shaped λ/4 short-circuited stubs operating in the range of i.e. 2.7 to 12.1 GHz with fractional bandwidth (FBW) 127%, and the TSIR is constructed using two T-shaped λ/2 open ended step impedance resonator (SIR) and one λ/4 short-circuited uniform impedance resonator (UIR) is coupled to the basic UWB design in order to achieve the stopbands performance at 5.1 GHz, 6 GHz, and 8 GHz, to supress the unwanted bands of WLAN, Wi-Fi 6E, and X-band satellite communication system, respectively. Commercial full-wave electromagnetic (EM) software HFSS-13 was used to design an ultra-compact structure having size 0.07 λg×0.02 λg on Rogers RT/Duroid 5880 substrate to justify good agreement between simulated and measured S-parameters.

A novel single-feed hybrid reconfigurable microstrip patch antenna for 5G mobile communication and radio frequency energy harvesting applications at 28/38GHz.

Reconfigurable antennas have received much attention in RF energy harvesting models owing to their selectivity for operating frequency and polarization. The characteristic of having frequency selectivity and polarization selectivity can be termed as frequency diversity and polarization diversity, respectively. This paper investigates a rectenna device with a new proposed topology in order to eliminate coupling between input and output lines and increase the rectification efficiency with the use of single feed hybrid reconfigurable antenna, switch between 28GHz and 38GHz frequency. Moreover, it is designed to charge a rechargeable battery of 1watt(W). The Reconfiguration mechanism is realized by electronically controlling different states of Switches. PIN Diode (as RLC Equivalent circuit) is used as a switch for ON/OFF states. This antenna mainly comprises rectangular shaped patches (28GHz and 38GHz) with Triango-Truncated edge at the corners. Eighteen PIN Diodes are placed symmetrically throughout the antenna presenting as, S1 & S2 for frequency reconfiguration, S3 to S6 & S7 to S10 connects Triango Truncated edge at the corners for polarization reconfiguration, and for radiation pattern reconfiguration at S11 to S14 & S15 to S18 has been used. The proposed antenna model is capable of simultaneously changing, the radiation patterns as clock and anti-clockwise directions at ±90-degree shift in E and H planes, circularly polarized (CP) states among, Linear Polarization (LP), Right Hand Circularly Polarization (RHCP), and Left Hand Circularly Polarization (LHCP). The current design describes using single antenna for energy harvesting and 5G mobile communication application. This would lead to higher output currents, leading to the ability to efficiently charge a wide variety of batteries. A fully functional prototype has been designed, fabricated and its compound reconfiguration characteristics have been validated for simulated and measured results. For validation of results, the experimental results and the simulation results from the proposed mathematical model were made into comparison, and excellent correlation between the measured and simulated results was obtained.

Enhanced tunable plasmonic resonance in crumpled graphene resonators loaded with gate tunable metamaterials.

Graphene devices have been widely explored for photonic applications, as they serve as promising candidates for controlling light interactions resulting in extreme confinement and tunability of graphene plasmons. The ubiquitous presence of surface crumples in graphene, very less is known on how the crumples in graphene can affect surface plasmon resonance and its absorption properties. In this article, a novel approach based on the crumpled graphene is investigated to realize broadband tunability of plasmonic resonance through the mechanical reconfiguration of crumpled graphene resonators. The mechanical reconfiguration of graphene crumples combined with dual electrostatic gating (i.e. raising the Fermi level from 0.2-0.4 eV) of graphene serves as a tuning knob enabling broad spectral tunability of plasmonic resonance in the wavelength range of 14-24 µm. The crumpled region in the resonators exhibits an effective trapping potential where it extremely confines the surface plasmonic field on the surfaces of crumples providing localized surface plasmon resonance at the apices of these crumples. Finally, to achieve near-unity absorption >99% at the resonance wavelengths (17 µm and 22 µm) crumpled graphene resonators are loaded with four ring shaped metamaterials which result in the enhanced near-field intensity of ≈1.4×106. This study delivers insight into the tunability of crumpled graphene and their coupling mechanism by providing a new platform for the flexible and gate tunable graphene sensors at the infrared region.

Dynamic Absorption Enhancement and Equivalent Resonant Circuit Modeling of Tunable Graphene-Metal Hybrid Antenna.

Plasmonic antennas are attractive optical components of the optoelectronic devices, operating in the far-infrared regime for sensing and imaging applications. However, low optical absorption hinders its potential applications, and their performance is limited due to fixed resonance frequency. In this article, a novel gate tunable graphene-metal hybrid plasmonic antenna with stacking configuration is proposed and investigated to achieve tunable performance over a broad range of frequencies with enhanced absorption characteristics. The hybrid graphene-metal antenna geometry is built up with a hexagon radiator that is supported by the Al2O3 insulator layer and graphene reflector. This stacked structure is deposited in the high resistive Si wafer substrate, and the hexagon radiator itself is a sandwich structure, which is composed of gold hexagon structure and two multilayer graphene stacks. The proposed antenna characteristics i.e., tunability of frequency, the efficiency corresponding to characteristics modes, and the tuning of absorption spectra, are evaluated by full-wave numerical simulations. Besides, the unity absorption peak that was realized through the proposed geometry is sensitive to the incident angle of TM-polarized incidence waves, which can flexibly shift the maxima of the absorption peak from 30 THz to 34 THz. Finally, an equivalent resonant circuit model for the investigated antenna based on the simulations results is designed to validate the antenna performance. Parametric analysis of the proposed antenna is carried out through altering the geometric parameters and graphene parameters in the Computer Simulation Technology (CST) studio. This clearly shows that the proposed antenna has a resonance frequency at 33 THz when the graphene sheet Fermi energy is increased to 0.3 eV by applying electrostatic gate voltage. The good agreement of the simulation and equivalent circuit model results makes the graphene-metal antenna suitable for the realization of far-infrared sensing and imaging device containing graphene antenna with enhanced performance.

Design and Investigation of Modern UWB-MIMO Antenna with Optimized Isolation.

This paper proposes a compact, semi-circular shaped multiple input multiple output (MIMO) antenna design with high isolation and enhanced bandwidth for ultrawide band (UWB) applications. A decoupling stub is used for high isolation reaching up to -55 dB over the entire bandwidth. The proposed antenna is used for UWB as well as super wide band (SWB) applications. The overall size of the proposed antenna is 18 × 36 × 1.6   mm3. The | S 11 |   and voltage standing wave ratio (VSWR) of the proposed antenna are less than -10 dB and 2, respectively, in the range of 3-40 GHz. The total impedance bandwidth of the proposed design is 37 GHz. The VSWR, | S 11 | , | S 22 | , | S 21 | , | S 12 | , gain, envelope correlation coefficient (ECC), radiation pattern, and various other characteristic parameters are discussed in detail. The proposed antenna is optimized and simulated in a computer simulation technology (CST) studio, and printed on a FR4 substrate.

Association of maternal hypertension with placental abruption.

BACKGROUND: Placental abruption is one of the leading causes of maternal mortality and morbidity. Many causes predispose an expecting mother to placental abruption, such as trauma, previous history, smoking, ethnicity and hypertension. The present study concentrated on maternal hypertension as a cause of abruption. METHODS: All subjects of this comparative study underwent a complete obstetrical clinical workup comprising history, general physical examination, abdominal and pelvic examination, and relevant investigations. The maternal condition was assessed and managed according to established labour ward protocols, which included both pharmacological and surgical intervention. Patients were allotted various subgroups for detailed data analysis and comparative analysis. RESULTS: A total of 50 cases and 50 controls for placental abruption were studied during the study period. Both groups were compared based on parity, gestational age, proteinurea, haemoglobin, and hypertension. Mean systolic blood pressure (SBP) of cases in this study was 155 +/- 7.8 mmHg versus mean SBP for controls was 120 +/-14 mmHg. Mean diastolic blood pressure (DBP) of the cases was 104 +/- 6.6 mmHg compared to controls where mean DBP was 71 +/-11 mmHg. Among the controls, 45 (90%) had blood pressures in the normal range. There was statistically significant differences between cases and controls with respect to hypertension (p < 0.01). CONCLUSION: Placental abruption is strongly associated with maternal hypertension.