Small Volume Research Articles

P-40 A rare cause of male infertility: 46, XX testicular disorder of sex development

Abstract Introduction 46, XX testicular disorder of sex development (DSD) is a rare condition with an estimated incidence of 1 per 20,000 individuals. The clinical spectrum ranges from ambiguous genitalia that is usually diagnosed at birth, to male infertility that is diagnosed in the adult years. However, the diagnosis of 46, XX DSD in an individual presenting with infertility may be challenging due to occult clinical findings. A thorough physical examination as well as clinical suspicion is required for diagnosis. Clinical Case A 22-year-old male presented to the urology clinic for infertility despite at least 3 years of regular unprotected intercourse. On physical examination, his testicles were palpable bilaterally in the scrotum with small volumes. Laboratory results revealed hypergonadotropic hypogonadism and his spermiogram revealed azoospermia. Abdominopelvic ultrosonagraphy (US) was reported normal except abdominal situs inversus. Tumor markers for a probable testicular tumor were negative. He was referred to medical genetic department. His family history was unremarkable except for parental consanguineouty. The chromosomal analyze revealed a 46, XX karyotype, and fluorescence in situ hybridization (FISH) disclosed that the SRY gene locus was translocated to the X chromosome: 46,x,der(x) t(x;Y) (sry+); SRY + AZF a,b,c microdeletion. The patient was consulted to the endocrinology department for further evaluation of hypogonadism. On physical exam, he had eunuchoid habitus with incomplete virilization, bilateral and symmetric gynecomastia. The height, and body mass index of the patient was 165 cm, and 29.2 kg/m2, respectively. The testicles were bilaterally palpable in the scrotum, with a volume of 4 mL each. His luteinizing hormone (LH), follicle-stimulating hormone (FSH) and total testosterone levels were 14 mUI/mL (laboratory reference: 1.5–9 mUI/mL), 42 mUI/mL (1.4–18 mUI/mL), and 140 ng/dl (197-700 ng/dL), respectively. The bone age matched his chronological age. Bone densitometry revealed osteopenia. A direct X-ray of the thorax showed thoracic situs inversus, he diagnosed with situs inversus totalis. Detailed genetic analyses could not be done concerning this diagnosis due to financial constraints. He had no history of lung infections that ruled out Kartagener's syndrome. Treatment was started with monthly intramuscular testosterone injections of 250 mg/ml. The patient and his family received genetic counseling, including advice that assisted reproduction will not work owing to AZFabc deletion. Conclusion 46, XX DSD is an uncommon genetic disorder that is rarely identified during the evaluation of male infertility. Clinical suspicion and a comprehensive physical exam are keys for diagnosis. Genetic analysis is essential for definitive diagnosis. A multidisciplinary is required for treatment and follow-up. Psychological support and genetic counseling are also critical for the management of these patients.

Method development for the quantification of nine nitazene analogs and brorphine in Dried Blood Spots utilizing liquid chromatography – tandem mass spectrometry

The detection of nitazenes in biological fluids is increasingly needed as they are repeatedly reported in intoxication and overdose cases. A simple method for the quantification of low levels of nine nitazene analogs and brorphine in Dried Blood Spots (DBS) was developed and validated. 10 μL of spiked whole blood is deposited on a Capitainer®B card and allowed to dry. The spot is punched out, and extracted with 500 μL methanol:acetonitrile (3:1 v/v) added with 1.5 μL of fentanyl-D5 as the internal standard. After stirring, sonication, and centrifugation of the vial, the solvent is dried under nitrogen, the extract is reconstituted in 30 μL methanol, and 1 μL is injected into a UHPLC-MS/MS instrument. The method validation showed linear calibration in the 1–50 ng/mL range, LOD values ranging between 0.3 ng/mL (isotonitazene) and 0.5 ng/mL (brorphine), average CV% and bias% within 15 % and 10 % for all compounds, respectively. The matrix effect due to blood and filter paper components was within 85–115 % while recovery was between 15–20 %. Stability tests against time and temperature showed no significant variations for storage periods up to 28 days. Room temperature proved to represent the best samples storage conditions. UHPLC-MS/MS proved capable to reliably identify all target analytes at low concentration even in small specimen volumes, as those obtained from DBS cards, which in turn confirmed to be effective and sustainable micro-sampling devices. This procedure improves the efficiency of toxicological testing and provides an innovative approach for the identification of the nitazene class of illicit compounds.

Influence of PCM configuration and optimization of PCM proportion on the thermal management of a prismatic battery with a combined PCM and air cooling structure

Different configurations and proportion of phase change material (PCM) have a vital impact on the thermal performance of the battery thermal management system (BTMS). In this work, the thermal performance of the battery pack is investigated by a combined PCM and air cooling technique. Firstly, four cases of PCM configuration are proposed to investigate the heat dissipation performance. Then PCM proportion is optimized to obtain better temperature uniformity, smaller energy loss and smaller amount of PCM based on Case 4. Finally, subjected to the installation space constraint of battery box (smaller volume), Case 5 is designed to diminish the volume of battery box and the corresponding thermal performance is discussed. The results show that thermal performance with PCM is superior than that without PCM; Case 4 not only enhances the thermal performance but also reduces the amount of PCM; The optimized PCM proportion is only 64 %; Compared with all PCM, the optimized ΔT, ΔP and PCM volume respectively reduce 11.91 % (0.83 K), 11.61 % (4.18 Pa) and 43.06 % (215,544 mm3); Case 5 not only shows more better thermal performance than Case 4 but also reduces 102,200 mm3 (3.48 %) volume of the battery box. The proposed strategy is effective for improving thermal performance of BTMS and saving the amount of PCM.

Review of: "Nanotechnology is the field of application of extremely small components next to each other. In the case of computers, the goal of putting these nanometer components together is to build faster, more powerful and smoother functioning computers in a smaller volume"

Review of: "Nanotechnology is the field of application of extremely small components next to each other. In the case of computers, the goal of putting these nanometer components together is to build faster, more powerful and smoother functioning computers in a smaller volume"

DSP based space vector PWM control for solar electric vehicle

Solar Electric Vehicles (SEV) are considered the future vehicles to solve the issues of air pollution, global warming, and the rapid decreases of the petroleum resources facing the current transportation technology. However, SEV are still facing important technical obstacles to overcome. They include batteries energy storage capacity, charging times, efficiency of the solar panels and electrical propulsion systems. Solving any of those problems and electric vehicles will compete-complement the internal combustion engines vehicles. In the present work, we propose an electrical propulsion system based on three phase induction motor in order to obtain the desired speed and torque with less power loss. Because of the need to lightweight nature, small volume, low cost, less maintenance and high efficiency system, a three phase squirrel cage induction motor (IM) is selected in the electrical propulsion system. The IM is fed from three phase inverter operated by a constant V/F control method and Space Vector Pulse Width Modulation (SVPWM) algorithm. The proposed control strategy has been implemented on the texas instruments TM320F2812 Digital Signal Processor (DSP) to generate SVPWM signal needed to trigger the gates of IGBT based inverter. The inverter used in this work is a three phase inverter IRAMY20UP60B type. The experimental results show the ability of the proposed control strategy to generate a three-phase sine wave signal with desired frequency. The proposed control strategy is experimented on a locally manufactured EV prototype. The results show that the EV prototype can be propelled to speed up to 60km/h under different road conditions.

Comparative evaluation of efficacy of 2% lidocaine containing adrenaline with and without hyaluronidase in inferior alveolar nerve blocks for patients requiring bilateral mandibular extractions

AbstractPurposeTo evaluate and compare the efficacy of 2% lidocaine containing adrenaline with and without hyaluronidase in inferior alveolar nerve blocks for patients requiring bilateral mandibular extractions.Patients and MethodsThis was the split‐mouth study conducted on 26 patients requiring bilateral mandibular teeth extraction. All the patients were assigned randomly to one of the two groups: (i) 2% lignocaine HCl + 1:2,00,000 adrenaline + hyaluronidase (75 IU) solution will be administered on one side which is the experimental side and (ii) 2% lignocaine HCl + 1:2,00,000 adrenaline solution on the other side is control side. In the first session, the patients randomly received the inferior alveolar nerve block with or without hyaluronidase in one side of the oral cavity. One week later, the same patient received the other technique which was not received in the first session. We also evaluated the onset, duration and need of any supplementary anaesthesia in both the groups.ResultsComparison of VAS score in the control group (2.73 ± 0.724) and experimental group (3 ± 0.693) showed statistically insignificant results (p = 0.177). Whereas the onset of local anaesthesia showed a statistically significant difference between the two groups (p < 0.001) mean of control group (2.73 ± 0.47) and experimental group (1.15 ± 0.23). Comparison of duration of anaesthesia showed a statistically significant difference (p < 0.001) with the mean duration of the experimental group being higher (106 ± 7.94) than the control group (86.27 ± 3.90). Comparison for the need for supplementary anaesthesia showed no statistically significant difference between the two groups.ConclusionWe conclude that if hyaluronidase is used, better blocks with smaller volumes are produced. LAs with hyaluronidase have been shown to improve the quality and effectiveness of anaesthetic blocks and shorten the time it takes for anaesthesia to begin, accelerate the onset of akinesia and lessen the need for additional anaesthesia. It also increases the duration of anaesthesia.

Real-time single-molecule imaging of transcriptional regulatory networks in living cells.

Gene regulatory networks drive the specific transcriptional programmes responsible for the diversification of cell types during the development of multicellular organisms. Although our knowledge of the genes involved in these dynamic networks has expanded rapidly, our understanding of how transcription is spatiotemporally regulated at the molecular level over a wide range of timescales in the small volume of the nucleus remains limited. Over the past few decades, advances in the field of single-molecule fluorescence imaging have enabled real-time behaviours of individual transcriptional components to be measured in living cells and organisms. These efforts are now shedding light on the dynamic mechanisms of transcription, revealing not only the temporal rules but also the spatial coordination of underlying molecular interactions during various biological events.

Milk microbiome transplantation: recolonizing donor milk with mother's own milk microbiota

Donor human milk (DHM) provides myriad nutritional and immunological benefits for preterm and low birthweight infants. However, pasteurization leaves DHM devoid of potentially beneficial milk microbiota. In the present study, we performed milk microbiome transplantation from freshly collected mother’s own milk (MOM) into pasteurized DHM. Small volumes of MOM (5%, 10%, or 30% v/v) were inoculated into pasteurized DHM and incubated at 37 °C for up to 8 h. Further, we compared microbiome recolonization in UV-C-treated and Holder-pasteurized DHM, as UV-C treatment has been shown to conserve important biochemical components of DHM that are lost during Holder pasteurization. Bacterial culture and viability-coupled metataxonomic sequencing were employed to assess the effectiveness of milk microbiome transplantation. Growth of transplanted MOM bacteria occurred rapidly in recolonized DHM samples; however, a greater level of growth was observed in Holder-pasteurized DHM compared to UV-C-treated DHM, potentially due to the conserved antimicrobial properties in UV-C-treated DHM. Viability-coupled metataxonomic analysis demonstrated similarity between recolonized DHM samples and fresh MOM samples, suggesting that the milk microbiome can be successfully transplanted into pasteurized DHM. These results highlight the potential of MOM microbiota transplantation to restore the microbial composition of UV-C-treated and Holder-pasteurized DHM and enhance the nutritional and immunological benefits of DHM for preterm and vulnerable infants.Key points• Mother’s own milk microbiome can be successfully transplanted into donor human milk.• Recolonization is equally successful in UV-C-treated and Holder-pasteurized milk.• Recolonization time should be restricted due to rapid bacterial growth.Graphical

Moderate active Fe3+ doping enables improved cationic and anionic redox reactions for wide-voltage-range sodium storage

Layered metal oxides are promising cathode materials for sodium-ion batteries (SIBs) due to their high theoretical specific capacity and wide Na+ diffusion channels. However, the irreversible phase transitions and cationic/anionic redoxes cause fast capacity decay. Herein, P2-type Na0.67Mg0.1Mn0.8Fe0.1O2 (NMMF-1) cathode material with moderate active Fe3+ doping has been designed for sodium storage. Uneven Mn3+/Mn4+distribution is observed in NMMF-1 and the introduction of Fe3+ is beneficial for reducing the Mn3+ contents both at the surface and in the bulk to alleviate the Jahn–Teller effect. The moderate Fe3+/Fe4+ redox can realize the best tradeoff between capacity and cyclability. Therefore, the NMMF-1 demonstrates a high capacity (174.7 mAh g−1 at 20 mA g−1) and improved cyclability (78.5% over 100 cycles) in a wide-voltage range of 1.5–4.5 V (vs. Na+/Na). In-situ X-ray diffraction reveals a complete solid-solution reaction with a small volume change of 1.7% during charge/discharge processes and the charge compensation is disclosed in detail. This study will provide new insights into designing high-capacity and stable layered oxide cathode materials for SIBs.

The D-SPECT SH reconstruction protocol: improved quantification of small left ventricle volumes

BackgroundDue to spatial resolution limitations, conventional NaI-SPECT typically overestimates the left ventricular (LV) ejection fraction (EF) in patients with small LV volumes. The purpose of this study was to explore the clinical application value of the small heart (SH) reconstruction protocol embedded in the postprocessing procedure of D-SPECT.MethodsWe retrospectively analyzed patients who undergo both D-SPECT and echocardiography (Echo) within one week. Patients with small LV volume were defined as those with a rest end-systolic volume (rESV) ≤ 25 mL and underwent reconstruction using the standard (SD) reconstruction protocol. The SH protocol was deemed successful in correcting the LVEF value if it decreased by 5% or more compared to the SD protocol. The ROC curve was used to calculate the optimal cutoff value of the SH protocol. LVEF, ESV and EDV were computed with SD and SH, respectively. Echo was performed as a reference, and Echo-LVEF, ESV, and EDV were calculated using the Teichholz formula. One-way ANOVA was used to compare these parameters among the three groups.ResultsThe final study included 209 patients (73.21% female, age 67.34 ± 7.85 years). Compared with the SD protocol, the SH protocol significantly decreased LVEF (67.43 ± 7.38% vs. 71.30 ± 7.61%, p < 0.001). The optimal cutoff value for using the SH protocol was rESV > 17 mL (AUC = 0.651, sensitivity = 78.43%, specificity = 45.57%, p = 0.001). In the subgroup of rESV > 17 mL, there was no significant difference in LVEF (61.84 ± 4.67% vs. 62.83 ± 2.85%, p = 0.481) between the SH protocol and Echo, and no significant difference was observed in rESV (26.92 ± 3.25 mL vs. 27.94 ± 7.96 mL, p = 0.60) between the SH protocol and Echo.ConclusionThis pilot study demonstrated that the SH reconstruction protocol was able to effectively correct the overestimation of LVEF in patients with small LV volumes. Particularly, in the rESV > 17 mL subgroup, the time and computing power waste could be reduced while still ensuring the accuracy of the LVEF value and image quality.

Stability simulation analysis of targeted puncture in L4/5 intervertebral space for PELD surgery.

Introduction: The application prospects of percutaneous endoscopic lumbar discectomy (PELD) as a minimally invasive spinal surgery method in the treatment of lumbar disc herniation are extensive. This study aims to find the optimal entry angle for the trephine at the L4/5 intervertebral space, which causes less lumbar damage and has greater postoperative stability. To achieve this, we conduct a three-dimensional simulated analysis of the degree of damage caused by targeted puncture-based trephine osteotomy on the lumbar spine. Methods: We gathered clinical CT data from patients to construct a lumbar model. This model was used to simulate and analyze the variations in trephine osteotomy volume resulting from targeted punctures at the L4/5 interspace. Furthermore, according to these variations in osteotomy volume, we created Finite Element Analysis (FEA) models specifically for the trephine osteotomy procedure. We then applied mechanical loads to conduct range of motion and von Mises stress analyses on the lumbar motion unit. Results: In percutaneous endoscopic interlaminar discectomy, the smallest osteotomy volume occurred with a 20° entry angle, close to the base of the spinous process. The volume increased at 30° and reached its largest at 40°. In percutaneous transforaminal endoscopic discectomy, the largest osteotomy volume was observed with a 50° entry angle, passing through the facet joints, with smaller volumes at 60° and the smallest at 70°. In FEA, M6 exhibited the most notable biomechanical decline, particularly during posterior extension and right rotation. M2 and M3 showed significant differences primarily in rotation, whereas the differences between M3 and M4 were most evident in posterior extension and right rotation. M5 displayed their highest stress levels primarily in posterior extension, with significant variations observed in right rotation alongside M4. Conclusion: The appropriate selection of entry sites can reduce lumbar damage and increase stability. We suggest employing targeted punctures at a 30° angle for PEID and at a 60° angle for PTED at the L4/5 intervertebral space. Additionally, reducing the degree of facet joint damage is crucial to enhance postoperative stability in lumbar vertebral motion units.

Design of a Deployable Broadband Mesh Reflector Antenna for a SIGINT Satellite System Considering Surface Shape Deformation.

In this paper, we propose a deployable broadband mesh reflector antenna for use in signals intelligence (SIGINT) satellite systems, considering performance degradation due to shape deformation. To maximize gain by increasing the diameter of the reflector while reducing the weight of the antenna, the reflector of the antenna is designed using lightweight silver-coated Teflon mesh. The mesh reflectors are typically expanded by tension to maintain their parabolic structure; thus, shape deformation cannot be avoided. This shape deformation results in shape differences between the surface of the mesh reflector and the ideal parabolic reflector, thus resulting in the degradation of the performance of the mesh reflector antenna. To observe this degradation, we analyze antenna performance according to the number of arms, the number of joints, the feed distance, and the distance from the reflector center to each joint. The performance of the mesh reflector antenna is examined using an effective lossy conducting surface (ELCS) that has the same reflectivity as the silver-coated Teflon mesh to reduce simulation time and computing resources. The designed silver-coated Teflon mesh reflector and the double-ridged feed antenna are fabricated, and the bore-sight gain is measured using the three-antenna method. The measured bore-sight gain of the proposed antenna is 31.6 dBi at 10 GHz, and the measured and simulated results show an average difference of 3.28 dB from 2 GHz to 18 GHz. The proposed deployable mesh reflector antenna can be used in a variety of applications where small stowed volume is required for mobility, such as mobile high-gain antennas as well as satellite antenna systems. Through this study, we demonstrate that shape deformation of the mesh reflector surface significantly affects the performance of reflector antennas.

Comparison of Otsu and an adapted Chan–Vese method to determine thyroid active volume using Monte Carlo generated SPECT images

BackgroundThe Otsu method and the Chan–Vese model are two methods proven to perform well in determining volumes of different organs and specific tissue fractions. This study aimed to compare the performance of the two methods regarding segmentation of active thyroid gland volumes, reflecting different clinical settings by varying the parameters: gland size, gland activity concentration, background activity concentration and gland activity concentration heterogeneity.MethodsA computed tomography was performed on three playdough thyroid phantoms with volumes 20, 35 and 50 ml. The image data were separated into playdough and water based on Hounsfield values. Sixty single photon emission computed tomography (SPECT) projections were simulated by Monte Carlo method with isotope Technetium-99 m (^{text {99m}}Tc). Linear combinations of SPECT images were made, generating 12 different combinations of volume and background: each with both homogeneous thyroid activity concentration and three hotspots of different relative activity concentrations (48 SPECT images in total). The relative background levels chosen were 5 %, 10 %, 15 % and 20 % of the phantom activity concentration and the hotspot activities were 100 % (homogeneous case) 150 %, 200 % and 250 %. Poisson noise, (coefficient of variation of 0.8 at a 20 % background level, scattering excluded), was added before reconstruction was done with the Monte Carlo-based SPECT reconstruction algorithm Sahlgrenska Academy reconstruction code (SARec). Two different segmentation algorithms were applied: Otsu’s threshold selection method and an adaptation of the Chan–Vese model for active contours without edges; the results were evaluated concerning relative volume, mean absolute error and standard deviation per thyroid volume, as well as dice similarity coefficient.ResultsBoth methods segment the images well and deviate similarly from the true volumes. They seem to slightly overestimate small volumes and underestimate large ones. Different background levels affect the two methods similarly as well. However, the Chan–Vese model deviates less and paired t-testing showed significant difference between distributions of dice similarity coefficients (p-value <0.01).ConclusionsThe investigations indicate that the Chan–Vese model performs better and is slightly more robust, while being more challenging to implement and use clinically. There is a trade-off between performance and user-friendliness.

Facile preparation of UiO-66-Lys/PAN nanofiber membrane by electrospinning for the removal of Co(II) from simulated radioactive wastewater

In this study, metal-organic framework (MOF) nanofiber membranes (NFMs) UiO-66-Lys/PAN were prepared by electrospinning using polyacrylonitrile (PAN) as the matrix, UiO-66-NH2 as the filler, and lysine (Lys) as the functional monomer. The membranes were subsequently employed to extract cobalt ions from simulated radioactive wastewater. The findings showed that the best performance of the membrane was obtained with a 3 % MOF content (3%UiO-66-Lys/PAN). Specifically, the pure water flux (PWF) of the 3 % UiO-66-Lys/PAN membrane reached 872 L m−2 h−1 with a cobalt ion retention of 45.4 %. In addition, adsorption experiments indicated that the NFMs had a theoretical maximum adsorption capacity of 41.4 mg/g for cobalt ions. The Langmuir isotherm model and the pseudo-second-order kinetic model were observed in the adsorption process, suggesting that the membrane material showed uniform adsorption of cobalt ions on a monolayer level, with an endothermic absorption process. XPS analysis confirmed that 3%UiO-66-Lys/PAN facilitated the adsorption of cobalt ions through a coordination effect, with the N and O atoms serving as coordinating atoms. Moreover, the material displayed excellent radiation stability even when exposed to doses ranging from 20 to 200 kGy. This study validated the stability of the MOF NFMs under real irradiation with radioactive nuclides (60Co) and demonstrated efficient cobalt ion separation. This study has important practical implications for the treatment and disposal of small volumes of 60Co-containing radioactive wastewater for engineering applications.

A high-throughput small volume matrix based calibration using isotope dilution liquid chromatography tandem mass spectrometry analysis for 42 per and polyfluoroalkyl substances in groundwater

A novel method for the determination of per- and polyfluoroalkyl substances (PFAS) in groundwater is presented using a subsample, matrix-matched calibrators, 96-well plate solid phase extraction (SPE), and ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Accuracy, precision, measurement of uncertainty (MOU), method detection limit (MDL), method quantitation limit (MQL), analytical measurement range, interferences/ion suppression, and analyte stability were determined as part of the in-house method validation. The method quantitates 42 PFAS compounds from nine different compound classes. Accuracy for the reference material (RM) and matrix spike (MS) ranged from 52.3 to 117.8 %, and precision for the MS and matrix spike duplicate (MSD) had a coefficient of variation (CV) from 2.0 % to 23.3 %. MDLs spanned from 0.07 to 1.97 ng L−1, with MQLs ranging from 0.20 to 5.90 ng L−1. Suppression studies determined that iron and manganese have effects on analytes that do not have paired isotopically labeled standards. The results from the in-house validation indicated that this Michigan Department of Health and Human Services laboratory developed test meets the necessary accuracy, precision, MDL, MQL and reporting limits requirement established by the laboratory's quality system essentials (QSEs) and select criteria from the Department of Defense (DoD) Quality Systems Manual for Environmental Laboratories and American Industrial Hygiene Association Laboratory Accreditation Program, LLC (AIHA LAP, LLC) accrediting International Standard Organization (ISO/IEC 17025:2017) check list.

Platelet-rich plasma - a revolutionary therapeutic option in multi-disciplinary indications

Background: Platelet-rich plasma (PRP) was originally described as a small volume of plasma that contains higher concentrations of platelets, compared to peripheral blood. Although currently the use of PRP in most indications is off-label, it is not prohibited. Initially, PRP was used for wound healing and tissue regeneration in fields such as orthopaedics, dermatology, maxillofacial surgery and dentistry.&#x0D; Aim of the study: The aim of this article was to present and summarise the modern production methods, the mechanism of action at the molecular and biochemical level and the most important uses and indications of PRP in present-day medicine.&#x0D; Material and methods: A cross-sectional search of relevant literature was performed in databases using accepted wording. Publications from 2003-2023 were included. The entire process has been supplemented with additional procedures to increase the reliability of this publication.&#x0D; Results: Orthopaedics has gained many minimally invasive therapeutic solutions thanks to PRP. Its effects on ligament and tendon tissues have been studied, where promising data have been proven. Also in aesthetic medicine and dermatology, many treatment strategies have been developed using PRP, mainly for the treatment of acne, androgenic alopecia and delaying tissue ageing as much as possible.&#x0D; Conclusion: Platelet-rich plasma has found application in the treatment of many conditions in orthopaedics, dermatology, aesthetic medicine and dentistry. It is characterised by good therapeutic efficacy, with relatively low risk. However, high-quality studies are still lacking to provide more reliable data.

THE SIMULTANEOUS QUANTIFICATION OF RIFAMPICIN AND ISONIAZID IN PATIENTS WITH TUBERCULOSIS APPLIED TO VOLUMETRIC ABSORPTIVE MICROSAMPLING DEVICES USING HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY

Objective: Rifampicin and isoniazid are the main tuberculosis treatment regimens requiring blood level measurement to optimize the treatment process. This study aims to analyze rifampicin and isoniazid quantitatively in volumetric absorptive microsampling (VAMS) prepared from a small volume of TB patients using HPLC. Methods: Analytes on the VAMS tip were extracted using 1000 ml of acetonitrile containing 10 µg/ml of cilostazol as an internal standard. Analytical separation was performed on the C-18 column at 40 ℃ with a mobile phase mixture of 50 mmol ammonium acetate buffer pH 5.0-acetonitrile-methanol (40:30:30), flow rate 0.5 ml/min. The analysis was carried out with the calibration curve over a range of 1.0–30 µg/ml for rifampicin and 0.4-20 µg/ml for isoniazid. Results: Analyte analysis in 21 patients showed that the measured value of rifampicin was 3.39–16.77 µg/ml, and isoniazid was 2.63–10.43 µg/ml at 2 h post-dose. 52.38% of patients had low blood concentrations in at least one of the drugs, 28.57% of the patients were in the therapeutic range, and 23.81% had a high blood concentration of isoniazid alone. Conclusion: The concentration of rifampicin and isoniazid in 21 tuberculosis patients varied. Dose adjustment is needed because most patients had low blood concentrations of one of the drugs, and a limited number had a high blood isoniazid concentration alone. Only some patients simultaneously had plasma concentrations within the target range of the drugs. This method was valid and reliably utilized for therapeutic drug monitoring of antituberculosis.

Physical temperature sensing of targets with shelters under indoor scenes by a revised Ku band microwave radiometer

This work is aimed to solve technical difficulties for microwave radiometers in Ku band and above under indoor scenes to detect physical temperatures of targets with shelters. Firstly, a revised microwave radiometer in Ku-band is developed with a novel calibration scheme. Secondly, in order to the designed radiometer pocess a high temperature accuracy for targets with shelters, crucial technical difficulties are investigated: 1) The long-neglected impact on temperature sensitivity of the single channel radiometer by the frequency stability of LO is analyzed and a LO with high frequency stability and small volume is designed. 2) The calibration accuracy deterioration caused by the receiver's nonideality is analyzed, and a novel calibration algorithm is proposed. 3) the method of plane wave spectrum (PWS) is proposed to derive the planar electric field in near field of the horn antenna for temperature inversion. 4) A more complete microwave thermal radiation transmission model of clothed human body is proposed. Thirdly, several experiments are set up and show that the designed radiometer can track physical temperatures of targets sheltered by cotton cloth relatively accurately, so that methods proposed for indoor near field applications are confirmed effective. Noteworthily, it is the first time in the microwave passive sensing domain that our work systematically proposes the temperature inversion theory for physical temperatures of targets with shelters accurately in noncontact under indoor scenes, and the design scheme for the microwave radiometer optimized portable along with a high temperature sensitivity applied for microwave security and medical monitoring.

Baroclinic factor in the stirring of waters of a sinking thermal with surrounding fresh water

The results of studying the process of stirring of a sinking thermal (small volume of denser water) with surrounding water are presented. The analysis of laboratory flows in a hydroflume has been allowed to identify the main peculiarities of the stirring of the thermal and the surrounding water. The essence of one of these features concluded in the presence of many high-gradient layers in the density field. The phase of an advective-rotational nature of the stirring of thermal waters with different density has been identified. Detailing of the evolution of the flow density structure was performed using the calculated flows on a 2d-nonlinear model of the dynamics of a fluid that is inhomogeneous in density. Features of the density structure are revealed using the values of local density gradients for the internal nodes of the computational grid. The density gradients along and across the streamlines were calculated. Quantitative estimates of the repeatability of high-gradient layers have shown significant variability in the flow density field. An analysis of the potential stability of the selected local regions of the flow has been carried out. The calculation of the Reynolds (Re) and Richardson (Ri) numbers has been allowed to assume a laminar nature of the flow, with the exception of two small zones in the back part of the sinking thermal. The role of the baroclinic mechanism of vorticity generation as a structure-forming factor in the formation of a distinguished stage of advective-vortex movement within interpenetration of thermal with surrounding water has shown.

Penetration of particles through vertical cracks

In a previous study, a new deposition model was developed to account for deposition of aerosol particles on the inner walls of small containers. In this article, the model applicability is extended by including deposition on horizontal surfaces, both upward-facing and downward-facing. After that, the model is applied to study a vital new issue, which is the penetration of aerosols to the indoors through vertical wall cracks. Previous studies, both theoretically and experimentally, never addressed penetration through vertical cracks. This study therefore aims to show the difference between penetration through vertical cracks and horizontal ones by applying the fourth-power model, which is very successful in describing deposition in small volumes. The penetration model formulated in this study takes into account, not only the thickness and depth of the crack, as usually happens in most penetration models, but all the three dimensions of the crack; thickness, depth and width. The obtained results are in a good agreement with the experimental data. This demonstrates the success of the extended fourth-power model in describing deposition inside cracks. Moreover, the results show a clear difference between vertical and horizontal cracks for the penetration of aerosols with diameter larger than ∼1μm. An application of the developed deposition and penetration models is presented, where a method for calculating the radioactive aerosols indoor concentrations is explained.