Virginity and Virginity Testing: Then and Now

Background: Despite the increasing progresses in medicine and health in the 21st century especially in the area of reproductive health, myths related to “virginity” and “virginity testing” still figure out life and death in some communities after centuries. Overall, aim of this study was to investigate the myths and objective facts associated with virginity and virginity testing.Methods: This review conducted by SID, Ovid, Science Direct, Pub Med, Pro Quest, Iran Medex, Google Scholar, Cochrane library, EBSCO, and United Nations Population Fund, WHO from 1980 to 2015. Keywords for search included virginity, virginity testing, hymen, sexual abstinence.Results: The undeniable value of virginity, female virginity worth versus the shame of virginity for male, the idea to preserve virginity despite oral and anal sex and indicators to assess the intact hymen and wedding night bleeding to prove virginity are misconceptions that besides perceived premarital sex as signs of civilization and conflicts of gender inequality and violence against women lead to fail most of approaches against increasing of premarital sex.Conclusion: Although programs such as "virginity pledge", "Silver Ring" and "Sexual abstinence education" are running in some countries, in order to expand virginity as a practical approach in controlling sexual transmitted diseases and teen pregnancy, the role of undeniable myths in advance to such approaches, the use of cultural, social and religious potentials of different societies to cope with the misconceptions and teaching of related objective facts seems necessary

Evaluating the performance characteristics of some ion chamber dosimeters in high dose per pulse intraoperative electron beam radiation therapy

Introduction: Employing routine dosimetry protocols for intraoperative electron beam needs further refinements to obtain reliable results. In this regard, the performance of some cylindrical and parallel plate ion chambers for both relative and absolute dosimetry of intraoperative electron beam has been evaluated. Materials and methods: Four different ion chambers including Semiflex and PinPoint cylindrical chambers as well as Advanced Markus and Roos parallel plate ones were employed for PDD measurement and dose rate determination in reference condition of the electron beam produced by LIAC intraoperative accelerator. The results of PDD measurements were compared with those of Gafchromic EBT2 film. Specific recommendations were followed to determine the chamber correction factors including k s and k Q,Q 0 for absolute dosimetry in intraoperative reference condition. Results: There was good agreement between PDDs measured by employed chambers and EBT2 film at all nominal energies. Nevertheless, Advanced Markus chamber had the best performance based on the gamma analysis results. Obtained k Q,Q 0 and k s for studied ion chambers largely differed from expected values by TRS-398 protocol. The difference of measured dose rates at 12 MeV energy by investigated chambers was less than 1.1 and Advanced Markus had the best accordance with pre-set dose rate by manufacture. Conclusion: Results showed that ignoring the specific recommended procedures in determining the chamber correction factors causes the overestimation of the measured dose. Therefore, dedicated dosimetry protocol should be developed for high dose per pulse intraoperative electron dosimetry including all of the updated correction factors and deviations from routine ionometric electron dosimetry formalisms. © 2019 Associazione Italiana di Fisica Medic

Phenotypic Identification and Genotypic Characterization of Plasmid‑Mediated AmpC β‑Lactamase‑Producing Escherichia coli and Klebsiella pneumoniae Isolates in Iran

One of the mechanisms of Klebsiella pneumoniae and Escherichia coli resistance to β-lactam antibiotics is the production of β-lactamase enzymes. Among these are the AmpC β-lactamases, which confer resistance to a class of antibiotics. However, little is known about the AmpC β-lactamases of K. pneumoniae and E. coli clinical isolates in Qazvin, Iran. This study was designed to assess the AmpC β-lactamases-producing strains and also identify the prevalence of AmpC β-lactamases genes. Antimicrobial susceptibility tests were performed on 435 K. pneumoniae and E. coli isolates using disk difusion technique. Plasmid-mediated AmpC genes were studied using a multiplex PCR assay. The AmpC β-lactamase-producer isolates were studied by employing cefoxitin disk difusion test, AmpC induction test, AmpC cefoxitin-EDTA test, and boronic acid disk test. Our results showed that of 46 (18.4%) cefoxitin-insensitive E. coli isolates, 10 (21.7%) were positive for AmpC β-lactamase genes, among them 4 (8.69%) isolates were positive for blaDHA genes and 6 (13%) for blaCIT genes. Of 57 (30.4%) cefoxitin-insensitive K. pneumoniae isolates, 10 (17.5%) were positive for AmpC gene with 4 (6.34%) and 6 (9.5%) isolates positive for blaDHA and blaCIT genes, respectively. However, no MOX, ACC, FOX, or EBC genes were detected in the isolates. Considering the results of diferent confrmatory phenotypic tests, the AmpC cefoxitin-EDTA test showed a higher discriminatory power for detecting AmpC β-lactamase-producing strains. The specifcity and sensitivity of AmpC cefoxitin-EDTA were 77%, 100% for K. pneumonia and 70%, 90% for E. coli higher than the other two tests, respectively. Also, the authors demonstrated high prevalence rate for resistance to certain antibiotics, such as cefuroxime, trimethoprim-sulfamethoxazole, ampicillin, and cefotaxime. In conclusion, our study provided valuable information regarding the plasmid-mediated AmpC β-lactamase gene content, antibiotic resistance, and confrmatory phenotypic tests for AmpC β-lactamases in E. coli and K. pneumoniae isolates from clinical sources

Interplay of pulse duration, peak intensity, and particle size in laser-driven electron emission from silica nanospheres

We present the results of a systematic study of photoelectron emission from gasphase dielectric nanoparticles (SiO2) irradiated by intense 25 fs, 780 nm linearly polarized laser pulses as a function of particle size (20 nm to 750 nm in diameter) and laser intensity. We also introduce an experimental technique to reduce the effects of focal volume averaging. The highest photoelectron energies show a strong size dependence, increasing by a factor of six over the range of particles sizes studied at a fixed intensity. For smaller particle sizes (up to 200 nm), our findings agree well with earlier results obtained with few-cycle, ~4 fs pulses. For large nanoparticles, which exhibit stronger near-field localization due to field-propagation effects, we observe the emission of much more energetic electrons, reaching energies up to ~200 times the ponderomotive energy. This strong deviation in maximum photoelectron energy is attributed to the increase in ionization and charge interaction for many-cycle pulses at similar intensities.Comment: 14 pages, 5 figure