Результаты поиска

The clinical biochemistry of aluminum.

The methods for aluminum analysis vary from the simple and often nonspecific chemical and physical procedures to the highly sophisticated types such as neutron activation and atomic absorption spectrometry. Atomic absorption procedures are the techniques of choice for most routine hospital laboratories. The wide distribution of aluminum in nature can create severe contamination problems in aluminum analysis. Procedures to avoid contamination are discussed. In recent years aluminum has been implicated as a possible etiological agent in DES and in Alzheimer's Disease. A common finding in these t

Survival of NASA-cleanroom microbial isolates under simulated space and Martian conditions.

Planetary protection hinges on understanding microbial survival following reduction procedures, the stressors of space travel, and exposure to extraterrestrial environmental conditions. This study identified 23 fungal strains isolated from NASA spacecraft assembly cleanrooms, capable of surviving ultraviolet radiation exposure. Using experimental simulation facilities, we conducted a comprehensive assessment of microbial survivability and morphology on the most resilient spacecraft-associated microorganisms. Aspergillus calidoustus demonstrated remarkable survival under simulated Martian condi

Unsupervised deep learning framework for early detection of wellbore trajectory deviation in drilling operations.

Wellbore trajectory deviation remains one of the major operational challenges encountered during directional and extended-reach drilling because even small departures from the planned well path can lead to poor reservoir placement, wellbore instability, increased non-productive time, and significant drilling costs. In most field operations, trajectory monitoring depends on periodic directional surveys together with threshold-based diagnostics. Although these methods are widely used, they often identify deviations only after they have become operationally noticeable, limiting the opportunity fo

Cluster Formation in the Superconducting Complex Intermetallic Compound Be21Pt5.

Materials with the crystal structure of γ-brass type (Cu5Zn8 type) are typical representatives of intermetallic compounds. From the electronic point of view, they are often interpreted using the valence electron concentration approach of Hume-Rothery, developed previously for transition metals. The γ-brass-type phases of the main-group elements are rather rare. The intermetallic compound Be21Pt5, a new member of this family, was synthesized, and its crystal structure, chemical bonding, and physical properties were characterized. Be21Pt5 crystallizes in the cubic space group F4̅3m with lattice

Interventions for the treatment of oral cavity and oropharyngeal cancer: radiotherapy.

BACKGROUND: The management of advanced oral cavity and oropharyngeal cancers is problematic and has traditionally relied on surgery and radiotherapy, both of which are associated with substantial adverse effects. Radiotherapy has been in use since the 1950s and has traditionally been given as single daily doses. This method of dividing up the total dose, or fractionation, has been modified over the years and a variety of approaches have been developed with the aim of improving survival whilst maintaining acceptable toxicity. OBJECTIVES: To determine which radiotherapy regimens for oral cavity

Sulfur X-ray absorption and vibrational spectroscopic study of sulfur dioxide, sulfite, and sulfonate solutions and of the substituted sulfonate ions X3CSO3- (X = H, Cl, F).

Sulfur K-edge X-ray absorption near-edge structure (XANES) spectra have been recorded and the S(1s) electron excitations evaluated by means of density functional theory-transition potential (DFT-TP) calculations to provide insight into the coordination, bonding, and electronic structure. The XANES spectra for the various species in sulfur dioxide and aqueous sodium sulfite solutions show considerable differences at different pH values in the environmentally important sulfite(IV) system. In strongly acidic (pH < approximately 1) aqueous sulfite solution the XANES spectra confirm that the hydrat

Novel methodology for the study of mercury methylation and reduction in sediments and water using 197Hg radiotracer.

Mercury tracers are powerful tools that can be used to study mercury transformations in environmental systems, particularly mercury methylat … when it is used it in short-term experiments and produced by the irradiation of 196Hg with thermal neutrons, using mercury targets with the natural isotopic composition. However, if the 0.15% natural abundance of the 196Hg isotope is increased, the specific activity of the 197Hg tracer can be significantly improved. In the present work, 197Hg tracer was p …

Effects of radiation and lifestyle factors on risks of urothelial carcinoma in the Life Span Study of atomic bomb survivors.

Among the Life Span Study (LSS) of Atomic-bomb survivors, recent estimates showed that unspecified bladder cancer had high radiation sensitivity with a notably high female-to-male excess relative risk (ERR) per radiation dose ratio and were the only sites for which the ERR did not decrease with attained age. These findings, however, did not consider lifestyle factors, which could potentially confound or modify the risk estimates. This study estimated the radiation risks of the most prevalent subtype of urinary tract cancer, urothelial carcinoma, while accounting for smoking, consumption of fru

Effects of calcium-deficient diets on manganese deposition in the central nervous system and bones of rats.

The presence of both aluminum (Al) and manganese (Mn) in central nervous system tissues (CNS) has been reported in Parkinson's disease and in parkinsonism-dementia (PD) on Guam. Epidemiological surveys on Guam have suggested that low calcium (Ca), magnesium (Mg) and high Al and Mn in river, soil and drinking water may be implicated in the pathogenesis of PD. Experimentally, low Ca-Mg diets with or without added Al have been found to accelerate Al deposition in the CNS of rats and monkeys. Although excessive deposition of Mn produces similar neurotoxic action to Al in CNS tissues, the mechanism

Heterogeneous Frustrated Lewis Pair Catalysts: Rational Structure Design and Mechanistic Elucidation Based on Intrinsic Properties of Supports.

ConspectusThe discovery of reversible hydrogenation using metal-free phosphoborate species in 2006 marked the official advent of frustrated Lewis pair (FLP) chemistry. This breakthrough revolutionized homogeneous catalysis approaches and paved the way for innovative catalytic strategies. The unique reactivity of FLPs is attributed to the Lewis base (LB) and Lewis acid (LA) sites either in spatial separation or in equilibrium, which actively react with molecules. Since 2010, heterogeneous FLP catalysts have gained increasing attention for their ability to enhance catalytic performance through t

Physicochemical characterization of polyoxyethylene (POE)-based nonionic surfactants in single and mixed micellar environments for anticancer drug solubilization enhancement.

This work reports the nanoscale micellar formation in single and mixed surfactant systems by combining an amphiphilic graft copolymer, Soluplus® (primary surfactant), blended with other polyoxyethylene (POE)-based nonionic surfactants such as Kolliphor® HS15, Kolliphor® EL, Tween-80, TPGS®, and Pluronics® P123 in an aqueous solution environment. The solution behaviour of these surfactants as a single system were analyzed in a wide range of surfactant concentrations and temperatures. Rheological measurements revealed distinct solution behaviour in the case of Soluplus®, ranging from low-viscosi

Amino acid transporter LAT1 (SLC7A5) as a molecular target for cancer diagnosis and therapeutics.

Cancer cells require a massive supply of nutrients, including sugars and amino acids-the upregulation of transporters for each nutrient contributes to meet the demand. Distinct from glucose transporters, amino acid transporters include ones whose expression is specific to cancer cells. For example, LAT1 (SLC7A5) displays protein expression mostly limited to the plasma membrane of cancer cells. The exceptions are the placental barrier and the blood-brain barrier, where immunohistochemical and mass spectrometric studies have shown LAT1 expression, although their levels are supposed to be lower t

Lifetime Mortality Risk from Cancer and Circulatory Disease Predicted from the Japanese Atomic Bomb Survivor Life Span Study Data Taking Account of Dose Measurement Error.

Dosimetric measurement error is known to potentially bias the magnitude of the dose response, and can also affect the shape of dose response. In this report, generalized relative and absolute rate models are fitted to the latest Japanese atomic bomb survivor solid cancer, leukemia and circulatory disease mortality data (followed from 1950 through 2003), with the latest (DS02R1) dosimetry, using Bayesian techniques to adjust for errors in dose estimates and assessing other model uncertainties. Linear-quadratic models are fitted and used to assess lifetime mortality risks for contemporary UK, US

Disarmed anthrax toxin delivers antisense oligonucleotides and siRNA with high efficiency and low toxicity.

Inefficient cytosolic delivery and vector toxicity contribute to the limited use of antisense oligonucleotides (ASOs) and siRNA as therapeutics. As anthrax toxin (Atx) accesses the cytosol, the purpose of this study was to evaluate the potential of disarmed Atx to deliver either ASOs or siRNA. We hypothesized that this delivery strategy would facilitate improved transfection efficiency while eliminating the toxicity seen for many vectors due to membrane destabilization. Atx complex formation with ASOs or siRNA was achieved via the in-frame fusion of either Saccharomyces cerevisiae GAL4 or Homo

High-spin cobalt(II) ions in square planar coordination: structures and magnetism of the oxysulfides Sr2CoO2Cu2S2 and Ba2CoO2Cu2S2 and their solid solution.

The antiferromagnetic structures of the layered oxychalcogenides (Sr(1-x)Ba(x))(2)CoO(2)Cu(2)S(2) (0 ≤ x ≤ 1) have been determined by powder neutron diffraction. In these compounds Co(2+) is coordinated by four oxide ions in a square plane and two sulfide ions at the apexes of an extremely tetragonally elongated octahedron; the polyhedra share oxide vertexes. The magnetic reflections present in the diffraction patterns can in all cases be indexed using a √2a × √2a × c expansion of the nuclear cell, and nearest-neighbor Co(2+) moments couple antiferromagnetically within the CoO(2) planes. The o

Management and outcome of patients with malignant salivary gland tumors.

PURPOSE: Refined imaging technology, the use of external beam radiation, neutron beam therapy, and chemotherapy, has altered management strategies for patients with salivary gland malignancies during the past 2 decades. Although treatment remains primarily surgical, optimal therapeutic regimens have yet to be fully realized. The purpose of this investigation is to report our experience with the management of patients with a variety of malignant salivary gland neoplasms that were treated with various combinations of surgery, radiation, and chemotherapy and to review treatment outcome in an effo

The various therapeutic applications of the medical isotope holmium-166: a narrative review.

Over the years, a broad spectrum of applications of the radionuclide holmium-166 as a medical isotope has been established. The isotope holmium-166 is attractive as it emits high-energy beta radiation which can be used for a therapeutic effect and gamma radiation which can be used for nuclear imaging purposes. Furthermore, holmium-165 can be visualized by MRI because of its paramagnetic properties and by CT because of its high density. Since holmium-165 has a natural abundance of 100%, the only by-product is metastable holmium-166 and no costly chemical purification steps are necessary for pro

Совпадение в полном тексте источника
… neutron activation of 164 Dy by two neutrons following a (2n, γ) reaction forming dysprosium-166 ( 166 Dy). … The 165 HoIG/PAN nanofibers were neutron activated and showed to be stable up to a thermal neutron-flux of approximately 3.5 × 10 12 neutrons/cm 2 s for at least 4 h at 100 °C. …

Multimodal analgesia and intravenous nutrition preserves total body protein following major upper gastrointestinal surgery.

BACKGROUND AND OBJECTIVES: This study examined whether perioperative multimodal analgesia (MMA) improves the effectiveness of intravenous nutrition (IVN) as a means of preventing protein wasting following major upper abdominal surgery (UAS). The MMA regimen utilized combined epidural opioid/local anesthetic and the systemic nonsteroidal anti-inflammatory drug (NSAID) ketorolac for 48 hours. METHODS: In a prospective, randomized, nonblinded study, 47 patients scheduled for major UAS were allocated to receive the following: MMA +/- intravenous lipid-based nutrition (IVN) or patient-controlled a

Radiation environment on TGO Mars orbit during solar particle events in January-October 2024. Corresponding solar eruptions and GOES proton fluxes data.

The dosimeter Liulin-MO for measuring the radiation environment on board the ExoMars Trace Gas Orbiter (TGO) is a module in the Fine Resolution Epithermal Neutron Detector (FREND). A number of solar energetic particle (SEP) events were observed in Mars orbit from July 2021 to 2024 during the increasing phase and close to the maximum of the 25th solar cycle activity. The results from the SEPs measurements obtained in 2021-2023 by Liulin-MO have been previously reported. Here we present the Liulin-MO results from the observation of the radiation parameters of the SEP events during January- Octob

Development and characterization of a prototype selenium-75 high dose rate brachytherapy source.

BACKGROUND: 75Se ( t 1 / 2 $t_{1/2}$ ≈ $\approx$ 120 days, E γ , avg $E_{\gamma,\text{avg}}$ ≈ $\approx$ 215 keV) offers advantages over 192Ir ( t 1 / 2 $t_{1/2}$ ≈ $\approx$ 74 days, E γ , avg $E_{\gamma,\text{avg}}$ ≈ $\approx$ 360 keV) as a high dose rate brachytherapy source due to its lower gamma energy and longer half-life. Despite its widespread use in industrial gamma radiography, a 75Se brachytherapy source has yet to be manufactured. PURPOSE: A novel 75Se-based source design with a vanadium diselenide core, titled the SeCure source, was proposed. This study aimed to