231 research outputs found
A 37 GHz Millimeter-Wave Antenna Array for 5G Communication Terminals
No full textThis work presents, design and specific absorption rate (SAR) analysis of a 37 GHz antenna, for 5th Generation (5G) applications. The proposed antenna comprises of 4-elements of rectangular patch and an even distribution. The radiating element is composed of copper material supported by Rogers RT5880 substrate of thickness, 0.254 mm, dielectric constant (εr), 2.2, and loss tangent, 0.0009. The 4-elements array antenna is compact in size with a dimension of 8 mm × 20 mm in length and width. The radiating patch is excited with a 50 ohms connector i.e., K-type. The antenna resonates in the frequency band of 37 GHz, that covers the 5G applications. The antenna behavior is studied both in free space and in the proximity of the human body. Three models of the human body, i.e., belly, hand, and head (contain skin, fat, muscles, and bone) are considered for on-body simulations. At resonant frequency, the antenna gives a boresight gain of 11.6 dB. The antenna radiates efficiently with a radiated efficiency of more than 90%. Also, it is observed that the antenna detunes to the lowest in the proximity of the human body, but still a good impedance matching is achieved considering the −10 dB criteria. Moreover, SAR is also being presented. The safe limit of 2 W/kg for any 10 g of biological tissue, specified by the European International Electro Technical Commission (IEC) has been considered. The calculated values of SAR for human body models, i.e., belly, hand and head are 1.82, 1.81 and 1.09 W/kg, respectively. The SAR values are less than the international recommendations for the three models. Furthermore, the simulated and measured results of the antenna are in close agreement, which makes it, a potential candidate for the fifth-generation smart phones and other handheld devices
State-of-the-Art Technologies, Challenges, and Prospects
No full textFunding Information: This review was prepared as part of research supported by the Alexander von Humboldt Foundation through a postdoctoral fellowship awarded to Dr. Muhammad Ali Inam. This work was financed by national funds from FCT—Fundação para a Ciência e a Tecnologia, I.P., under the scope of the project UID/50006/2023 of the Associate Laboratory for Green Chemistry—LAQV REQUIMTE. Publisher Copyright: © 2025 by the authors.The contamination of drinking water sources with selenium (Se) oxyanions, including selenite (Se(IV)) and selenate (Se(VI)), contains serious health hazards with an oral intake exceeding 400 µg/day and therefore requires urgent attention. Various natural and anthropogenic sources are responsible for high Se concentrations in aquatic environments. In addition, the chemical behavior and speciation of selenium can vary noticeably depending on the origin of the source water. The Se(VI) oxyanion is more soluble and therefore more abundant in surface water. Se levels in contaminated waters often exceed 50 µg/L and may reach several hundred µg/L, well above drinking water limits set by the World Health Organization (40 µg/L) and Germany (10 µg/L), as well as typical industrial discharge limits (5–10 µg/L). Overall, Se is difficult to remove using conventionally available physical, chemical, and biological treatment technologies. The recent literature has therefore highlighted promising advancements in Se removal using emerging technologies. These include advanced physical separation methods such as membrane-based treatment systems and engineered nanomaterials for selective Se decontamination. Additionally, other integrated approaches incorporating photocatalysis coupled adsorption processes, and bio-electrochemical systems have also demonstrated high efficiency in redox transformation and capturing of Se from contaminated water bodies. These innovative strategies may offer enhanced selectivity, removal, and recovery potential for Se-containing species. Here, a current review outlines the sources, distribution, and chemical behavior of Se in natural waters, along with its toxicity and associated health risks. It also provides a broad and multi-perspective assessment of conventional as well as emerging physical, chemical, and biological approaches for Se removal and/or recovery with further prospects for integrated and sustainable strategies.publishersversionpublishe
Emerging Trends of Methicillin-Resistant Staphylococcus aureus: A Tertiary Care Hospital-Based Study
No full textObjective: To analyze the frequency and antimicrobial susceptibility patterns of Methicillin-resistant Staphylococcus aureus (MRSA) in a tertiary care hospital in Lahore, Pakistan.
Methodology: A retrospective study was conducted from October 2020 to December 2021 in a tertiary care hospital in Lahore, Pakistan. The clinical specimens meeting the inclusion criteria underwent processing in the microbiology section of a tertiary care hospital in Lahore, Pakistan, following the CLSI 2021 standards. Identification of all Methicillin-resistant Staphylococcus aureus (MRSA) isolates was conducted using standard laboratory procedures. Antibiotic susceptibility testing was performed utilizing the modified Kirby-Bauer disc diffusion method, with E-strips employed for vancomycin assessment.
Results: A total of 65 Staphylococcus aureus specimens were isolated. Among these, 49% were identified as Methicillin-resistant Staphylococcus aureus (MRSA). The majority of MRSA isolates (56%) were found in males, and a significant proportion (59%) fell within the age range of 21-60 years. Pus specimens accounted for the highest frequency (78%) among all samples. Notably, all MRSA isolates exhibited 100% resistance to beta-lactam drugs and combination therapies such as penicillin, cephalosporin, carbapenem, and amoxicillin-clavulanic acid. Conversely, Linezolid demonstrated complete sensitivity, while Chloramphenicol showed a sensitivity rate of 93%. Fluoroquinolones and aminoglycosides displayed a sensitivity of up to 50%. Additionally, the minimum inhibitory concentration (MIC) for vancomycin indicated sensitivity across all study isolates.
Conclusion: The study concluded that MRSA is continuously on the rise, with increasing resistance and limiting the antibiotic options for the treatment of these superbugs
Optimization of Antimony Removal by Coagulation-Flocculation-Sedimentation Process Using Response Surface Methodology
No full textCoprecipitation-adsorption plays a significant role during coagulation-flocculation-sedimentation (C/F/S) of antimony (Sb) in water. This work uses a Box–Behnken statistical experiment design (BBD) and response surface methodology (RSM) to investigate the effects of major operating variables such as initial Sb(III, V) concentration (100–1000 µg/L), ferric chloride (FC) dose (5–50 mg/L), and pH (4–10) on redox Sb species. Experimental data of Sb(III, V) removal were used to determine response function coefficients. The model response value (Sb removal) showed good agreement with the experimental results. FC showed promising coagulation behavior of both Sb species under optimum pH (6.5–7.5) due to its high affinity towards Sb species and low residual Fe concentration. However, a high dose of 50 mg/L of FC is required for the maximum (88–93%) removal of Sb(V), but also for the highest (92–98%) removal of low initial concentrations of Sb(III). Furthermore, BBD and RSM were found to be reliable and feasible for determining the optimum conditions for Sb removal from environmental water samples by a C/F/S process. This work may contribute to a better understanding and prediction of the C/F/S behavior of Sb(III, V) species in aqueous environments, to reduce potential risks to humans
De novo primary squamous cell carcinoma of the ovary: A case of a rare malignancy with an aggressive clinical course
No full textOvarian squamous cell carcinoma is a rare malignancy and the occurrence is attributable to malignant transformation of an existing ovarian dermoid cyst. The de novo occurrence of squamous cell carcinoma of the ovary, in the absence of an antecedent ovarian dermoid, is extremely rare. The case of a 31 year old Asian woman, evaluated for abdominal distension and discomfort is presented. Abdominal CT was suggestive of a malignant neoplastic process. Laparotomy confirmed a malignant tumour with involvement of the right adnexa and extension into the omentum and bowel. Surgical debulking, hysterectomy, bilateral salpingo-ophorectomy and total omentectomy and bowel resection was performed. Histopathology demonstrated squamous cell carcinoma arising from the right ovary with no co-existing ovarian dermoid. The postoperative period was significant for disease progression despite adjuvant chemotherapy
Comparing Methods and Finding H. pylori Infections and their Resistance to Beta Lactam Drugs as Seen in Peshawar, Pakistan
No full textThe aims of this study were to find and report pattern of resistance towards beta lactam antibiotics in patients infected with H. pylori by visiting Hayatabad Medical Complex (HMC). Diagnostic procedures like: gastroendoscopy, Rapid Urease Test (RUT), biochemical testing, microscopic examination, antibacterial sensitivity tests and molecular methods were utilized and compared. Polymerase chain reaction was used to find 16S rRNA gene fragment. Hundred forty-four patients were found H. pylori positive for urease and 182 were positive for catalase. Hundred and thirty-two were positive for oxidase while hundred eighty were Gram negative. By polymerase chain reaction, 16S rRNA gene fragment was found to be positive in 164 subjects. The pattern of antibiotics resistance in H. pylori as seen in Peshawar, Pakistan in 200 gastric biopsies. A poorer resistance level towards amoxicillin is noticeable as due to low socioeconomic conditions
Photocatalytic Activity of Al2O3.Fe2O3 Synthesized by Ultrasonic-Assisted Mechanical Stirring
No full textSynthesis and Photocatalytic Efficiency of Sunlight Driven Novel Ternary Metal Oxide Nanophotocatalyst
No full textKinetic and isothermal sorption of antimony oxyanions onto iron hydroxide during water treatment by coagulation process
No full textComparison of Tramadol Versus Bupivacaine as Local Anesthetic in Pain Control in Inguinal Hernia Surgery
No full textObjective: To compare the outcomes of local infiltration of tramadol versus bupivacaine for postoperative pain control and time to mobilize patients out of bed with less intravenous analgesia consumption in inguinal hernia surgery.
Methodology: This randomized controlled trial was conducted at the Department of General Surgery, Pakistan Institute of Medical Sciences (PIMS), Islamabad September 2018 to August 2019. A total of 122 patients who were randomly allocated to either Group A (tramadol) or Group B (bupivacaine).
Data on postoperative pain scores (VAS at 3, 6, 12, 24 hours), time to first analgesia, and time to mobilization were collected using a structured proforma and analyzed with SPSS version 26.
Results: In the bupivacaine group, mean age was 34 ± 9 years; in the tramadol group, 31 ± 8 years. At 24 hours post-surgery, mean pain score was 5.2 ± 1 in bupivacaine and 2.7 ± 0.5 in tramadol. Tramadol showed significantly lower mean pain at 3rd, 6th, 12th, and 24th hours (p < 0.001). Time to first analgesia was 10 ± 7 hours in bupivacaine and 13.5 ± 5.6 hours in tramadol, indicating a statistically longer duration for tramadol (p < 0.05). Mobilization time was 9 ± 4 hours in bupivacaine and 6 ± 4.5 hours in tramadol, with tramadol showing significantly lower time to mobilize (p < 0.001).
Conclusion: Tramadol local infiltration is effective in reducing pain, delaying analgesia need, and promoting earlier mobilization compared to bupivacaine. Consideration of tramadol at wound closure for inguinal hernia repair may enhance outcomes and patient satisfactio
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