Browsing by Author "Lalit Kumar"

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14.5: PIC simulation of a Gyrotron-traveling-wave tube amplifier
(2010) Simhadri Uma Maheswara Reddy; Vemula Bhanu Naidu; S.K. Datta; P.K. Jain; Lalit Kumar
Nonlinear analysis of a high-power gyro-TWT amplifier operating in TE01 mode has been investigated through particle-in-cell (PIC) simulation using CST-studio. The simulation results are validated against published results with close accuracy. The simulation predicts 150 kW output power at 34 GHz with 21% efficiency, 48 dB saturated gain and 1.3 GHz bandwidth. © 2010 IEEE.
A Comparison Between Intravesical Gemcitabine Plus Docetaxel and Intravesical Bacillus Calmette-Guérin in the Treatment of Nonmuscle Invasive Naive Urinary Bladder Cancer: A Systematic Review and Meta-analysis of Oncological Outcomes
(2025) Rachana Tripathy; Lalit Kumar; Sakshi Agarwal; Anuja Thakur; Mahesh R. Khairnar; Sameer Trivedi; Satya Narayan Sankhwar
This study evaluated the efficacy, recurrence rates, and safety of intravesical gemcitabine plus docetaxel compared to standard Bacillus Calmette-Guérin (BCG) therapy for treating naïve non-muscle-invasive bladder cancer (NMIBC), with a focus on reducing recurrence and progression concerns associated with transurethral resection (TURBT). A systematic review and meta-analysis of three original studies were conducted, assessing recurrence rates and safety profiles. The meta-analysis revealed no heterogeneity in recurrence rates between the gemcitabine plus docetaxel and BCG groups, with an overall Odds Ratio for recurrence of 0.72 (95% CI: 0.36-1.47). Although the clinical recurrence rate was slightly lower in the gemcitabine plus docetaxel group, the difference was not statistically significant (Z = 0.89, P = 0.37). The gemcitabine plus docetaxel group experienced fewer severe side effects compared to the BCG group. Due to the limited number of studies available, further randomized trials are necessary to confirm the role of intravesical gemcitabine plus docetaxel in NMIBC management. © © 2025 Elsevier Inc. All rights reserved.
A Comparison Between Intravesical Gemcitabine Plus Docetaxel and Intravesical Bacillus Calmette-Guérin in the Treatment of Nonmuscle Invasive Naive Urinary Bladder Cancer: A Systematic Review and Meta-analysis of Oncological Outcomes
(Elsevier Inc., 2025) Rachana Tripathy; Lalit Kumar; Sakshi Agarwal; Anuja Thakur; Mahesh R. Khairnar; Sameer Trivedi; Satya Narayan Sankhwar
This study evaluated the efficacy, recurrence rates, and safety of intravesical gemcitabine plus docetaxel compared to standard Bacillus Calmette-Guérin (BCG) therapy for treating naïve non-muscle-invasive bladder cancer (NMIBC), with a focus on reducing recurrence and progression concerns associated with transurethral resection (TURBT). A systematic review and meta-analysis of three original studies were conducted, assessing recurrence rates and safety profiles. The meta-analysis revealed no heterogeneity in recurrence rates between the gemcitabine plus docetaxel and BCG groups, with an overall Odds Ratio for recurrence of 0.72 (95% CI: 0.36–1.47). Although the clinical recurrence rate was slightly lower in the gemcitabine plus docetaxel group, the difference was not statistically significant (Z = 0.89, P = 0.37). The gemcitabine plus docetaxel group experienced fewer severe side effects compared to the BCG group. Due to the limited number of studies available, further randomized trials are necessary to confirm the role of intravesical gemcitabine plus docetaxel in NMIBC management. © 2025 Elsevier Inc.
A cost-effective modified split graft technique using bovine pericardium after plaque excision in Peyronie's disease - An initial experience
(Wolters Kluwer Medknow Publications, 2025) Lalit Kumar; Anil Baliyan; Aviral Srivastava; Anuja Thakur; Sameer Trivedi
Aims: The plaque excision and grating technique is indicated for correcting penile curvature in Peyronie's disease. We assessed our experience of the modified split graft technique using bovine pericardium after plaque excision. Materials and Methods: Between March 2020 and September 2024, we operated on 12 patients by the excision of plaque and split grafting technique. Here, we discuss our experience customizing a bovine pericardium graft on a table according to the size of the defect and joining pieces of graft and tunica albuginea with a Polydioxanone (PDS) suture to cover the cavernosal defect. Results: Patients' mean age and follow-up were 48 years and 30 months, respectively. The average size of the plaque and penile curvature was 4.6 cm (range 1.5-8 cm) and 45°, respectively. No residual penile curvature was observed in 83.5% of patients while (16.5%) had curvature of <20°. All patients experienced an improvement in stretched penile length with an average increase of 1.6 cm. Seventy-five percent of patients were able to perform sexual activity without assistance after 3 months. One patient, who had a sizeable cavernosal defect of 8 cm × 2 cm, experienced severe postoperative erectile dysfunction (ED) along with residual penile curvature of 15° and required semi-rigid penile prosthesis. Two patients having mild ED was managed by Tadalafil 10 mg. Another patient with residual chordee of <20° was managed on conservative therapy. Conclusions: In our limited experience, this modified split graft technique using bovine pericardium after plaque excision seems feasible, cost-effective, and safe. It has comparable outcomes to the standard methods reported in the literature and reduces graft material wastage. Further, long-term randomized trials are needed to validate its long-term efficacy and safety compared to conventional grafting approaches. © 2025 Urology Annals.
A Medical Marvel And Complex Clinical Scenario: The Largest Documented Case of Renal Metastasis from Pleomorphic Adenoma, Weighing 13.5 kg
(Springer, 2025) Lalit Kumar; Rohan Shankar; Neha Singh; Tarun K. Batra
Renal masses weighing as much as 13.5 kg are uncommon in the era of radiological imaging. A 52-year-old male presented with a left renal and parotid tumor with a history of parotidectomy 30 years back. He had an open radical nephrectomy followed by total parotidectomy. The patient had an uneventful recovery without any complications. The histopathology report of the renal tumor came as pleomorphic adenoma, while parotidectomy as carcinoma ex pleomorphic adenoma. This case highlights the indolent nature of pleomorphic adenoma presenting as delayed, huge renal metastasis. The thorough evaluation, accurate diagnosis, surgical excision of the tumor, and long-term close surveillance in pleomorphic adenoma are essential. © The Author(s), under exclusive licence to Indian Association of Surgical Oncology 2025.
A simple algorithm for large-signal analysis of a Gyro-TWT
(2007) Santanu Karmakar; P.K. Jain; Lalit Kumar; B.N. Basu
This paper presents a simple self consistent Large-Signal formulation for computation of saturated gain, power and saturation length of a Gyro-TWT. A computer code has been developed in C++ language. The computed results were found to be matching with the reported results obtained from other formulation. Using this code, a Gyro-TWT interaction structure has been designed at 35 GHz with Beam voltage of 50 kV.
Analysis of dielectric loss in a helix slow-wave structure
(Defense Scientific Information and Documentation Centre, 2009) S.K. Datta; Lalit Kumar; B.N. Basu
Equivalent circuit analysis of a helix slow-wave structure was carried out and closed form expressions were derived for the shunt capacitance and shunt conductance per unit length of the transmission-line equivalent circuit of the structure. These equivalent circuit parameters were interpreted for the dielectric attenuation constant of the slow-wave structure. The analysis was computationally simple and showsed excellent agreement with published results. The analysis was furthered for predicting the dielectric loss in typical C-Ku band and Ka band helical slow-wave structures, and variation of dielectric loss with temperature. © 2009, DESIDOC.
Analysis of qRT-PCR Data to Identify the Most Stable Reference Gene Using gQuant
(Bio-protocol LLC, 2025) Abhay Kumar Pathak; Sukhad Kural; Shweta K. Singh; Lalit Kumar; Manjari Gupta; Garima Jain
The accurate quantification of nucleic acid–based biomarkers, including long non-coding RNAs (lncRNAs), messenger RNAs (mRNAs), and microRNAs (miRNAs), is essential for disease diagnostics and risk assessment across the biological spectrum. Quantitative reverse transcription PCR (qRT-PCR) is the gold standard assay for the quantitative measurement of RNA expression levels, but its reliability depends on selecting stable reference targets for normalization. Yet, the lack of consensus on a universally accepted reference gene for a given sample type or species, despite being necessary for accurate quantification, presents a challenge to the broad application of such biomarkers. Various tools are currently being used to identify a stably expressed gene by using qRT-PCR data of a few potential normalizer genes. However, existing tools for normalizer gene selection are fraught with both statistical limitations and inadequate graphical user interfaces for data visualization. gQuant, the tool presented here, essentially overcomes these limitations. The tool is structured in two key components: the preprocessing component and the data analysis component. The preprocessing addresses missing values in the given dataset by the imputation strategies. After data preprocessing, normalizer genes are ranked using democratic strategies that integrate predictions from multiple statistical methods. The effectiveness of gQuant was validated through data available online as well as in-house data derived from urinary exosomal miRNA expression datasets. Comparative analysis against existing tools demonstrated that gQuant delivers more stable and consistent rankings of normalizer genes. With its promising performance, gQuant enhances the precision and reproducibility in the identification of normalizer genes across diverse research scenarios, addressing key limitations of RNA biomarker–based translational research. © 2025 The Authors.
ASO Author Reflections: Reevaluating Muscle Invasion in Bladder Cancer: The Role of VI-RADS in Guiding Re-resections/ Re-stage TURBT
(Springer Science and Business Media Deutschland GmbH, 2025) Sukhad Kural; Lalit Kumar
[No abstract available]
Assessing the clinical efficacy of neoadjuvant intravesical Mitomycin C in naïve non-muscle invasive urinary bladder cancer: A systematic review and meta-analysis
(Elsevier Inc., 2025) Anuja Thakur; Lalit Kumar; Sakshi Agarwal; Rachana Tripathy; Yashasvi Singh; Sameer Trivedi; Ujwal Kumar
Background and Objective: Naïve non-muscle invasive bladder cancer (NMIBC) is commonly treated with transurethral resection (TURBT), but recurrence and progression remain concerns. This meta-analysis, the first we have conducted on this topic, compared recurrence and progression rates between patients treated with neoadjuvant Mitomycin C (MMC) and the control group (TURBT alone). Methods: Relevant articles were identified and appraised through a structured literature assessment. Databases searched included PubMed, Medline, Scopus, and Science Direct. Duplicate publications, book sections, conference papers, encyclopedias, case reports, magazine articles, presentations, theses, protocols, systematic reviews, and meta-analyses were excluded. Heterogeneity was assessed using the I2. Key findings and limitations: The meta-analysis evaluated recurrence rates, progression rates, and adverse events. No heterogeneity was observed (I2=0 %). The pooled odd ratio (OR) for recurrence was 2.554 (95 % CI: 1.637-3.986), indicating a significant decrease in recurrence for the MMC group (P < 0.001). For progression rates, the overall pooled OR was 1.508 (95 % CI: 0.832-2.734), suggesting that the MMC group showed a lower progression rate. However, this difference was not statistically significant (P = 0.176).Adverse events varied, with the MMC group showing fewer cases of hematuria (8.4 % vs. 34 %) but more irritative bladder symptoms. Conclusions and Clinical Implications: The meta-analysis suggests lower recurrence and progression rates in the neoadjuvant MMC group compared to the control group. Both groups experienced a comparable range of adverse events, suggesting that both treatment approaches exhibit a similar safety profile. Larger and more randomized controlled trials (RCT) are needed to confirm MMC's effectiveness in NIMBC treatment and establish its role in clinical practice. © 2025 Elsevier Inc.
Assessment of Short-Term Outcomes in Children with Chronic Kidney Disease: Cohort Study
(Springer, 2025) Ram Babu; Lalit Kumar; Ankur Singh; Vaibhav Pandey; Shefali Agarwal; Anil Kumar; Rajniti Prasad; Abhishek Abinay; Shivender Singh
[No abstract available]
Buccal versus Vaginal Graft Urethroplasty in Female Urethral Stricture: A Systematic Review and Meta-Analysis
(Springer Nature, 2025) Lalit Kumar; Anuja Thakur; Sakshi Agarwal; Mahesh R. Khairnar; Sameer Trivedi; Satya Narain Shankhwar
Introduction and Hypothesis: This study is aimed at comparing success rate, maximum flow rate (Qmax), and post-void residual volume (PVR) between the buccal mucosal graft (BMG) and vaginal wall graft (VWG) through a meta-analysis of studies commonly performed by urogynecologists. Methods: A systematic review was performed in April 2024, including retrospective, prospective, and comparative studies excluding duplicates, review, editorial comments, case reports, systematic reviews, meta-analyses, and therapeutic indications. Heterogeneity in the meta-analysis was assessed using I2 statistics. Results: The meta-analysis incorporated a quantitative assessment of 18 original articles. The studies in meta-analysis evaluated various parameters, including Qmax, PVR, and success rates of surgical outcomes. The I2 statistics indicated no heterogeneity in Qmax and success rates between BMG and VWG, both with I2 = 0% and high heterogeneity for PVR values (I2 > 50%). According to the results, Qmax values were 23.266 for BMG and 24.945 for VWG, PVR values were 14.651 for BMG and 23.009 for VWG, and success rates were 86.2% for BMG and 89.8% for VWG. A definition of success across the studies was established by achieving Qmax > 15 ml/s at 3 months, a PVR < 30 ml, and an improvement in the American Urological Association symptom scores. Conclusions: Meta-analysis indicates no significant differences between VWG and BMG regarding Qmax, PVR, and the overall success rate of surgical outcomes. Both BMG and VWG graft options demonstrate effectiveness in female urethroplasty. Graft choice should be based on graft availability and feasibility, patient characteristics, and the surgeon’s preference and expertise. © The Author(s), under exclusive license to International Urogynecological Association 2025.
Characterization of vane-loaded cylindrical wave guiding structure using NRP technique by simulated experiment
(IEEE Computer Society, 2009) S. Umamaheswara Reddy; P. Raja Ramana Rao; Bhanu Naidu; Lalit Kumar; P.K. Jain
There is a lot of interest in vane-loaded cylindrical wave-guiding structures for fast-wave devices. Dispersion and interaction impedance are the two basic characteristics defining the structures for their relative merits and demerits for an intended application. A mmwave vane loaded structure is evaluated for these parameters by using a non-resonant perturbation (NRP) technique. The results are compared with the results obtained from analysis and simulation.
Climatology of the occurrences of thundery weather over Gauhati airport
(Birkhäuser-Verlag, 1972) Lalit Kumar; H.S. Rathor
The probability of occurrences of thundery weather over Gauhati airport has been investigated. During the pre-monsoon thunderstorm period, the months of April and May have higher probabilities for the occurrences of thundery weather and the month of March has, on average, medium probabilities. The probability for thundery weather, during the months of March and April, is the highest during >18 to 24 h and then decreases successively during 00 to 06 h, >12 to 18 h and >06 to 12 h in order. The month of May, being the transition season for sharp decrease of nor' westers, is an exception. The months June to September, during monsoon season, have high probabilities for a day being thundery; but the month of October, during which monsoon virtually withdraws, shows decreasing trend in probabilities for successive date-groups. During the whole of the monsoon months, the time-groups >12 to 18 h, >18 to 24 h, 00 to 06 h and >06 to 12 h rank first, second, third and fourth in the order of probability for a day being thundery. In April and May, the probabilities for the occurrences of thundery weather of MLL, LL and VLL groups are higher, but in the month of March, the probabilities for the occurrences of first two groups are higher and the third group has medium probability. During the months June to September, in the monsoon season, the probability for thundery weather of MLL and LL groups are higher but that of VLL group has the medium probability; during the month of October - the last month for monsoon season - MLL and LL have higher and medium probabilities for the occurrences of thundery weather. © 1972 Birkhäuser Verlag.
Combination neoadjuvant therapy with toripalimab and axitinib for renal cell carcinoma with inferior vena cava thrombus: Insights from the NEOTAX study
(Wolters Kluwer Medknow Publications, 2025) Lalit Kumar
The NEOTAX trial is a phase 2, open-label, single-arm study conducted at a single center in China between March 2020 and October 2023. It evaluated the efficacy and safety of toripalimab‑based neoadjuvant therapy, a PD-1 inhibitor, with axitinib, a vascular endothelial growth factor receptor-tyrosine kinase inhibitor (TKI), in patients with clear cell renal cell carcinoma (ccRCC) and inferior vena cava tumor thrombus (IVC-TT). Patients received toripalimab 240 mg intravenously every 3 weeks (up to 4 cycles), in combination with axitinib 5 mg orally twice daily. The primary endpoint was the down-staging rate of the IVC-TT level, evaluated after 12 weeks of neoadjuvant therapy and immediately prior to surgery. The secondary endpoints included changes in thrombus length, overall tumor response according to the RECIST criteria, surgical approach modifications, progression-free survival (PFS), safety, and biomarker analyses. Twenty-five patients with Mayo levels II–IV IVC-TT were enrolled. The median age of the 25 patients was 58 years (76% male). Clinical stages included T3b (56%), T3c (36%), and T4 (8%). Lymph node metastasis was present in 40% of patients and 25% had distant metastasis. The median tumor thrombus length was 9.5 cm. © 2025 Indian Journal of Urology
Comparison of Electrocautery Versus Ultrasonic Shears in Laparoscopic Nephrectomy: a Pilot Randomized Controlled Trial
(Springer, 2021) Lalit Kumar; Harshit Garg; Manoj Kumar; Rishi Nayyar; Brusabhanu Nayak; Rajeev Kumar
Novel energy devices such as ultrasonic shears (US) are widely used in laparoscopic surgery due to convenience and outcomes. However, these are expensive and add to the procedure cost. Electrocautery (EC) can often provide similar surgical outcomes and existing literature in unclear on the benefits of one over the other. We conducted a randomized trial between US and EC use in laparoscopic nephrectomy. Twenty patients undergoing laparoscopic nephrectomy between January 2019 and January 2020 at our tertiary referral center were included. Patients were randomly allocated in 2 groups according to energy used, i.e., EC and US. We assessed operative time, blood loss, intra- and postoperative complications, drain output and duration, hospital stay, readmission rates within 30 days of discharge, and surgeon satisfaction with the instruments used. The mean operative time and estimated blood loss were 113 min and 170 ml in EC group while 106 min and 180 ml in US group (p > 0.05). The mean change in hematocrit values after surgery were 6.12% and 5.27% in EC and US group, respectively (p = 0.812). There were no significant differences in mean hospital stay (2.7 in EC group, 2 days in US group), drain output (35.6 ml in EC and 26.3 ml in US group), and drain duration (1.7 days in EC and 1.9 days in US group). One patient in EC group had retroperitoneal hematoma due to Veress needle injury. Similarly only 1 patient in US group had severe intraoperative bleeding requiring conversion to open procedure. Two patients in the EC group had postoperative complications, i.e., fever and purulent collection under surgical site. Electrocautery and ultrasonic shears appear to be comparable in efficacy and safety in laparoscopic nephrectomy. However larger prospective studies are required to confirm our findings. © 2020, Association of Surgeons of India.
Development of a robust and generalizable algorithm "gQuant" for accurate normalizer gene selection in qRT-PCR analysis
(Nature Research, 2024) Abhay Kumar Pathak; Sukhad Kural; Shweta Singh; Lalit Kumar; Mahima Yadav; Manjari Gupta; Parimal Das; Garima Jain
The emergent role of nucleic acid-based biomarkers—microRNAs(miRNAs), long non-coding RNAs(lncRNAs), and messenger RNAs(mRNAs), is becoming increasingly prominent in disease diagnostics and risk assessment. qRT-PCR is the primary analytical method for quantitative measurement of biomarkers. Yet, the relative infancy of non-coding RNAs recognition as biomarkers poses a challenge due to the absence of a consensus on a universally accepted normalizer gene, an absolute requirement for accurate quantification. Current tools normalizer selection are fraught with statistical limitations and suboptimal graphical user interface for data visualisation. These deficiencies underscore the necessity for a balanced tool tailored to handle qRT-PCR datasets. Addressing the identified challenges, we have developed 'gQuant' tool crafted to address these limitations. We employed voting classifiers that combine predictions from multiple statistical methods. Tool's efficacy was validated through different available and in house data derived from urinary exosomal miRNAs datasets. Comparative analysis with existing tools revealed that their integrated methodologies could skew the ranking of normalizer genes, whereas 'gQuant' consistently yielded rankings characterised by lower standard-deviation, reduced covariance, and enhanced kernel density estimation values. Given 'gQuant's' promising performance, normalizer gene identification will be greatly improved, improving precision of gene expression quantification in a variety of research scenarios. The gQuant tool developed for this study is available for public use and can be accessed at [https://github.com/ABHAYHBB/gQuant-Tool]." © The Author(s) 2024.
Efficacy in Using Urodynamic Parameters of Intravesical Electrical Stimulation for Detrusor Underactivity
(AVES, 2025) Anil Kmar; Aviral Sivastava; Rachana Tripathy; Lalit Kumar; Yashasvi Singh; Ujwal Kumar; Sameer Trivedi; Satya Narayan Sankhwar
[No abstract available]
Forecasting thunderstorms and hailstorms by means of temperature and dew-point anomalies on a time-section chart
(Birkhäuser-Verlag, 1971) Lalit Kumar; H.S. Rathor
Vertical time-section charts for temperature and dew-point anomalies have been plotted. The temperature anomaly decreasing upwards give convection according to Byers and Braham [1]2). The coincidence of temperature anomalies with central minimum and of dew-point anomalies with central maximum, or of upward decreasing trend in temperature anomalies and upward increasing trend in dewpoint anomalies, correspond to the convection associated with greater moisture influx, thus representing the case of a thunderstorm. The mentioned anomalies have been found to occur in such a way that cells with central maximum are followed by those with central minimum, and vice versa. Thus simultaneous occurrences of upward decreasing anomalies in temperature, i.e. occurrence of cells with central minimum of temperature, and upward increasing anomalies in dew-point, i.e. occurrence of cells with central maximum, can be observed at any station, hence the occurrences of thunderstorms at that station can be predicted. Moreover, the two kinds of anomalies can give the idea (along with that of convection, of coming of the synoptic situation having dry air aloft and moist air below, which is the ideal condition) for the occurrence of a hailstorm (Fawbush and Miller [2]). © 1971 Birkhäuser Verlag.
Integrating miRNA profiling and machine learning for improved prostate cancer diagnosis
(Nature Research, 2025) Shweta K. Singh; Abhay Kumar Pathak; Sukhad Kural; Lalit Kumar; Madan Gopal Bhardwaj; Mahima L. Yadav; Sameer Trivedi; Parimal Das; Manjari Gupta; Garima Jain
Prostate cancer (PCa) diagnosis remains challenging due to overlapping clinical features with benign prostatic hyperplasia (BPH) and limitations of existing diagnostic tools like PSA tests, which yield high false-positive rates. This study investigates the potential of microRNA (miRNA) biomarkers, analyzed via reverse transcription polymerase chain reaction and machine learning (ML), to enhance diagnostic accuracy. miRNAs such as miR-21-5p, miR-141-3p, and miR-221-3p were identified as significant discriminators between PCa and BPH through a prospective cohort study. Whole blood miRNA profiling offered a robust systemic representation of disease states. A random forest ML model was trained on expression data, achieving notable performance metrics: an accuracy of 77.42%, AUC of 0.78 during verification, and 74.07% accuracy and 0.75 AUC in validation. The model’s use of miRNA expression ratios, such as miR-141-3p/miR-221-3p, demonstrated superior sensitivity and specificity over traditional PSA testing. Bioinformatics analysis confirmed the association of selected miRNAs with cancer pathways, including PD-L1/PD-1 checkpoint and androgen receptor signaling, validating the biological relevance of the findings. This novel integration of miRNA profiling and machine learning holds great potential for the clinical translation of miRNA-based non-invasive diagnostics, enhancing diagnostic precision. However, broader population studies and standardization of protocols are needed to ensure scalability and clinical applicability. This research provides a foundational framework for advancing miRNA-based diagnostics, bridging discovery and clinical implementation. © The Author(s) 2025.