The photophysical properties of the β-barrel superfolder green fluorescent protein (sfGFP) arise from the chromophore that forms post-translationally in the interior of the protein. Specifically, the protonation state of the side chain of tyrosine 66 in the chromophore, in addition to the network of hydrogen bonds between the chromophore and surrounding residues, is directly related to the electronic absorbance and emission properties of the protein. The pH dependence of the photophysical properties of this protein were modulated by the genetic, site-specific incorporation of 3-nitro-l-tyrosine (mNOY) at site 66 in sfGFP.
View Article and Find Full Text PDFWe present a reduced-order model to calculate response matrices rapidly for filter stack spectrometers (FSSs). The reduced-order model allows response matrices to be built modularly from a set of pre-computed photon and electron transport and scattering calculations through various filter and detector materials. While these modular response matrices are not appropriate for high-fidelity analysis of experimental data, they encode sufficient physics to be used as a forward model in design optimization studies of FSSs, particularly for machine learning approaches that require sampling and testing a large number of FSS designs.
View Article and Find Full Text PDFWe demonstrate the application of neural networks to perform x-ray spectra unfolding from data collected by filter stack spectrometers. A filter stack spectrometer consists of a series of filter-detector pairs, where the detectors behind each filter measure the energy deposition through each layer as photo-stimulated luminescence (PSL). The network is trained on synthetic data, assuming x-rays of energies <1 MeV and of two different distribution functions (Maxwellian and Gaussian) and the corresponding measured PSL values obtained from five different filter stack spectrometer designs.
View Article and Find Full Text PDFThe multi-decade neutron dosimeter and imaging diagnostic (MDND) is a passive diagnostic that utilizes the polyethylene (n, p) nuclear reaction to enhance the diagnostic's sensitivity for time and energy integrated neutron measurements in the range of 2.45-14.1 MeV.
View Article and Find Full Text PDFRev Sci Instrum
February 2024
We present an inversion method capable of robustly unfolding MeV x-ray spectra from filter stack spectrometer (FSS) data without requiring an a priori specification of a spectral shape or arbitrary termination of the algorithm. Our inversion method is based upon the perturbative minimization (PM) algorithm, which has previously been shown to be capable of unfolding x-ray transmission data, albeit for a limited regime in which the x-ray mass attenuation coefficient of the filter material increases monotonically with x-ray energy. Our inversion method improves upon the PM algorithm through regular smoothing of the candidate spectrum and by adding stochasticity to the search.
View Article and Find Full Text PDFNitrocellulose is a reactive derivative of cellulose, one of the most commonly occurring natural materials. Nitration of cellulose decreases the stability of the structure, meaning less is understood about its structure and reactions. Although cellulose is often found in fully crystalline forms, nitrocellulose is more commonly paracrystalline, or amorphous.
View Article and Find Full Text PDFThe original version of this article unfortunately contained mistakes. The complete list of corrections is given below.
View Article and Find Full Text PDFBackground: Zika virus (ZIKV) has become a global concern because infection of pregnant mothers was linked to congenital birth defects. Zika virus is unique from other flaviviruses, because it is transmitted vertically and sexually in addition to by mosquito vectors. Prior studies in mice, nonhuman primates, and humans have shown that ZIKV targets the testis in males, resulting in persistent infection and oligospermia.
View Article and Find Full Text PDFObjective: To investigate factors associated with early IVF treatment discontinuation.
Design: Retrospective cohort study.
Setting: Academic medical center.
Plastic production has increased exponentially since its use became widespread in the 1950s. This has led to increased concern as plastics have become prevalent in the oceanic environment, and evidence of their impacts on marine organisms and human health has been highlighted. Despite their prevalence, very few long-term (>40 years) records of the distribution and temporal trends of plastics in the world's oceans exist.
View Article and Find Full Text PDFPurpose: Implantation failure is a major limiting factor of successful in vitro fertilization (IVF). The objective of this study was to determine if endometrial mechanical stimulation (EMS) by endometrial biopsy in the luteal phase of the cycle prior to embryo transfer (ET) improves clinical outcomes in an unselected subfertile population.
Methods: Double-blind, randomized controlled trial of EMS versus sham biopsy and odds of clinical pregnancy after IVF and embryo transfer.
Objective: To demonstrate a unique case of direct ultrasound-guided follicle aspiration at time of a laparotomy in a patient with Mayer-Rokitansky-Küster-Hauser Syndrome.
Design: Video presentation.
Setting: Academic fertility center PATIENT(S): A 32-year-old gravida 0 with Mayer-Rokitansky-Küster-Hauser Syndrome and bilateral ovarian masses presented as a fertility preservation consult from gynecologic oncology due to the possibility of bilateral oophorectomy.
Purpose: To elicit patient preferences for social media utilization and content in the infertility clinic.
Methods: This was a cross-sectional survey study conducted in three US fertility practices. Women presenting to the infertility clinic for an initial or return visit were offered an anonymous voluntary social media survey.
Background The UK sports drinks market has a turnover in excess of £200 million. Adolescents consume 15.6% of total energy as free sugars, much higher than the recommended 5%.
View Article and Find Full Text PDFNeutron dosimetry in reactor fields is currently mainly conducted with unwieldy flux monitors. Tissue Equivalent Proportional Counters (TEPCs) have been shown to have the potential to improve the accuracy of neutron dosimetry in these fields, and Multi-Element Tissue Equivalent Proportional Counters (METEPCs) could reduce the size of instrumentation required to do so. Complexity of current METEPC designs has inhibited their use beyond research.
View Article and Find Full Text PDFThe worldwide upward trend in obesity has been dramatic, now affecting more than 20% of American women of reproductive age. Obesity is associated with many adverse maternal and fetal effects prenatally, but it also exerts a negative influence on female fertility. Obese women are more likely to have ovulatory dysfunction due to dysregulation of the hypothalamic-pituitary-ovarian axis.
View Article and Find Full Text PDFBackground Sports drinks intended to improve performance and hydrate athletes taking part in endurance sport are being marketed to children, for whom these products are not intended. Popularity among children has grown exponentially. Worryingly they consume them socially, as well as during physical activity.
View Article and Find Full Text PDFObesity is associated with a myriad of adverse reproductive outcomes including miscarriage, fetal growth abnormalities, and preeclampsia. While the mechanisms involved are likely multifactorial, the potential impact of obesity on the preimplantation embryonic trophoblast cannot be overlooked-particularly given the role the trophoblast plays in endometrial invasion and implantation. Appropriate trophoblast function is critical in establishing a normal pregnancy.
View Article and Find Full Text PDFUltrasonic blades have been shown to cause less acute electrophysiological damage when applied near nerves than monopolar electrosurgery (ES). This study was performed to determine whether the acute nerve damage observed for ES, as well as the relative lack of damage observed for ultrasonic dissection, extends through a subacute timeframe. Muscle incisions were made in rat with the Harmonic(®) Blade (HB) and ES at a distance of 2 mm from the sciatic nerve.
View Article and Find Full Text PDFAs applications for IVF have expanded over the years, so too have approaches to controlled ovarian stimulation (COS) for IVF. With this expansion and improved knowledge of basic reproductive biology, there is increasing interest in how COS practice influences IVF outcomes, and whether or not specific treatment scenarios call for personalized approaches to COS. For the majority of women undergoing COS and their treating physicians, the goal is to achieve a healthy live birth through IVF in a fresh cycle.
View Article and Find Full Text PDFBackground: Ultrasonic surgical devices have been demonstrated to provide excellent hemostasis, efficient transection, minimal lateral thermal damage, low smoke generation, and no risk of electrical current passage to the patient. These benefits originate from the inherent characteristics of the ultrasonic mechanism, but further improvements were thought possible through optimization of the energy delivery during application. The study reported here compared a new ultrasonic device, Harmonic ACE®+ Shears with Adaptive Tissue Technology, with a commercial predicate device, Harmonic ACE® Shears (both Ethicon Endo-Surgery, Inc.
View Article and Find Full Text PDFObjective: The aim of this study was to evaluate patients' barriers against colorectal cancer screening tests and to assess patients' preferences and cost influences for CT colonography (CTC) in a nonadherent urban subpopulation.
Subjects And Methods: Patients who had been offered colorectal cancer screening but were nonadherent were asked to participate in this questionnaire study. Patients' demographic information was obtained, and patients' reasons for not being screened were explored.
Testosterone (T) can influence both male-male competition and mate choice displays. In zebra finches, female mate choice is based in part on bill color, and bill color has been shown to be enhanced by long-term testosterone supplementation. However, it is not clear whether bill color plays a role in male-male interactions and how bill color responds to shorter-term changes in T.
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