1.Monte Carlo study of transmission X-ray tubes in kilovoltage radiotherapy
Yikai WU ; Zhongyu QI ; Li TAO ; Hui ZHANG ; Zeeshan MUHAMMAD ; Zirui YE ; Yankui CHANG ; Xi PEI ; Xu GEORGE
Chinese Journal of Medical Physics 2025;42(7):863-871
Transmission X-ray tubes are relatively new devices characterized by portability,suitability for miniaturization,and low requirements for shielding,making them ideal radiation sources for kilovoltage X-ray therapy.However,their application in radiotherapy remains underexplored.An electron target model of a transmission X-ray tube is developed using the Monte Carlo toolkit TOPAS 3.8.1.The study investigates the effect of tungsten target thickness on X-ray output efficiency,finding that a tube voltage of 50 kV and a tungsten thickness of 1.4 μm yields the highest emission efficiency.Based on the energy spectrum at this optimal efficiency,polynomial fitting approach is applied to determine the corresponding aluminum filter thickness for mean energies ranging from 20 keV to 35 keV,achieving a mean fitting error of 0.91%.Next,the study simulates dose deposition in a water phantom for spectra with different mean energies and various source-to-surface distances,and plots percent-depth-dose curves,relative normalized dose-depth curves,and relative normalized dose histograms under each treatment condition.Finally,the simulated results are compared with experimental data from the intraoperative radiotherapy system Intrabeam and the superficial X-ray therapy unit SRT-100,obtaining average relative errors of 3.71%and 4.38%,respectively.These findings provide a theoretical foundation for further optimization of transmission X-ray tubes in kilovoltage radiotherapy.
2.Monte Carlo study of transmission X-ray tubes in kilovoltage radiotherapy
Yikai WU ; Zhongyu QI ; Li TAO ; Hui ZHANG ; Zeeshan MUHAMMAD ; Zirui YE ; Yankui CHANG ; Xi PEI ; Xu GEORGE
Chinese Journal of Medical Physics 2025;42(7):863-871
Transmission X-ray tubes are relatively new devices characterized by portability,suitability for miniaturization,and low requirements for shielding,making them ideal radiation sources for kilovoltage X-ray therapy.However,their application in radiotherapy remains underexplored.An electron target model of a transmission X-ray tube is developed using the Monte Carlo toolkit TOPAS 3.8.1.The study investigates the effect of tungsten target thickness on X-ray output efficiency,finding that a tube voltage of 50 kV and a tungsten thickness of 1.4 μm yields the highest emission efficiency.Based on the energy spectrum at this optimal efficiency,polynomial fitting approach is applied to determine the corresponding aluminum filter thickness for mean energies ranging from 20 keV to 35 keV,achieving a mean fitting error of 0.91%.Next,the study simulates dose deposition in a water phantom for spectra with different mean energies and various source-to-surface distances,and plots percent-depth-dose curves,relative normalized dose-depth curves,and relative normalized dose histograms under each treatment condition.Finally,the simulated results are compared with experimental data from the intraoperative radiotherapy system Intrabeam and the superficial X-ray therapy unit SRT-100,obtaining average relative errors of 3.71%and 4.38%,respectively.These findings provide a theoretical foundation for further optimization of transmission X-ray tubes in kilovoltage radiotherapy.
3.Psychiatric Comorbidities in Adults with DiGeorge Syndrome
Hiren PATEL ; Ramu VADUKAPURAM ; Zeeshan MANSURI ; Chintan TRIVEDI ; Kanwarjeet Singh BRAR ; Uzma BEG ; Jigar PATEL ; Aalamgeer IBRAHIM ; Muhammad Khalid ZAFAR
Clinical Psychopharmacology and Neuroscience 2022;20(3):498-503
Objective:
DiGeorge Syndrome (DGS) is a common multisystem disorder associated with deletions on chromosome 22q11.2. Our objective is to evaluate the psychiatric comorbidities and demographics of patients suffering from DGS in a nationally representative dataset on inpatient hospitalizations.
Methods:
The Nationwide Inpatient Sample for the year 2005−2017 was used for this study. Data on patients with DiGeorge syndrome were collected by using the International Classification of Diseases code. Univariate and multivariate logistic regression analysis was performed.
Results:
In our study, the average age was 30.4 years (n = 6,563), with 59.9% male, and 61.8% of patients were white. There was a high prevalence of mood disorders (24.7%) and anxiety disorders (16.4%), followed by schizophrenia and other psychotic condition (14.0%). In patients with mood disorders, 8% had Major Depressive Disorder, and 7% had bipolar depression. Overall composite of psychiatric comorbidities was present in 2,959 (45.1%) of patients. The mean length of stay was 6.58 days, and 77% of patients had routine discharge to home. In the adjusted analysis, the average length of stay was 8.6 days vs. 6.7 days (p < 0.001) in patients with and without psychiatry comorbidities.In comparison to routine discharge, patients with psychiatry comorbidities were more likely to be discharged to other healthcare facilities (odds ratio [OR]: 1.28, p < 0.001) and discharged against medical advice (OR: 3.45, p < 0.001).
Conclusion
Patients with DGS have worse outcomes with a higher rate of discharge to other healthcare facilities and a higher rate of being discharged against medical advice. Further large scale randomize studies are indicated.
4.Potential medicinal plants involved in inhibiting 3CLpro activity: A practical alternate approach to combating COVID-19.
Fan YANG ; Xiao-Lan JIANG ; Akash TARIQ ; Sehrish SADIA ; Zeeshan AHMED ; Jordi SARDANS ; Muhammad ALEEM ; Riaz ULLAH ; Rainer W BUSSMANN
Journal of Integrative Medicine 2022;20(6):488-496
At present, a variety of vaccines have been approved, and existing antiviral drugs are being tested to find an effective treatment for coronavirus disease 2019 (COVID-19). However, no standardized treatment has yet been approved by the World Health Organization. The virally encoded chymotrypsin-like protease (3CLpro) from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which facilitates the replication of SARS-CoV in the host cells, is one potential pharmacological target for the development of anti-SARS drugs. Online search engines, such as Web of Science, Google Scholar, Scopus and PubMed, were used to retrieve data on the traditional uses of medicinal plants and their inhibitory effects against the SARS-CoV 3CLpro. Various pure compounds, including polyphenols, terpenoids, chalcones, alkaloids, biflavonoids, flavanones, anthraquinones and glycosides, have shown potent inhibition of SARS-CoV-2 3CLpro activity with 50% inhibitory concentration (IC50) values ranging from 2-44 µg/mL. Interestingly, most of these active compounds, including xanthoangelol E (isolated from Angelica keiskei), dieckol 1 (isolated from Ecklonia cava), amentoflavone (isolated from Torreya nucifera), celastrol, pristimerin, tingenone and iguesterin (isolated from Tripterygium regelii), tannic acid (isolated from Camellia sinensis), and theaflavin-3,3'-digallate, 3-isotheaflav1in-3 gallate and dihydrotanshinone I (isolated from Salvia miltiorrhiza), had IC50 values of less than 15 µg/mL. Kinetic mechanistic studies of several active compounds revealed that their mode of inhibition was dose-dependent and competitive, with Ki values ranging from 2.4-43.8 μmol/L. Given the significance of plant-based compounds and the many promising results obtained, there is still need to explore the phytochemical and mechanistic potentials of plants and their products. These medicinal plants could serve as an effective inexpensive nutraceutical for the general public to help manage COVID-19.
SARS-CoV-2
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Plants, Medicinal
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COVID-19 Drug Treatment

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