Various Types Of Specimens Research Articles

Development of acoustic impedance tube system using 3D printing and finite element analysis

This study aims to demonstrate and provide a practical guide on correctly designing, fabricating, and verifying the acoustic impedance tube system. Many parts required to build this tube system were uniquely designed and 3D printed, such as the driver case, specimen holder, microphone holder, etc. In addition, this acoustic tube is designed to meet three functions: standard sound absorption measurement, in-situ measurement, and microphone mismatch measurement. Various types of specimens are tested to verify the accuracy of the measurement and how it compares to the poroelastic theoretical models and FEM models. To estimate the poroelastic parameters, measurement and FEM models were used to run the optimization process. The validation study shows good agreement in all three cases: measurement, the poroelastic model, and the FEM model.

Improvement in Mechanical Properties of Completely Decomposed Granite Soil Concrete Fabricated with Pre-Setting Pressurization.

This paper investigates the effectiveness of applying continuous high-compression pressure on the initial setting of fresh concrete to produce hardened concrete materials with excellent mechanical properties. A novel experimental apparatus was self-designed and used for the pre-setting pressure application. The utilization of the completely decomposed granite (CDG) soil as an alternative aggregate in concrete production was also explored. A total of twenty-eight specimens were fabricated using two types of fine aggregates, six mix ratios, two initial pressure values, and two distinct durations of the initial pressure application. The density and uniaxial compressive strength (UCS) of the specimens were examined to evaluate their mechanical qualities, while micro-CT tests with image analysis were used to quantify their porosity. The results indicated that the 10 MPa initial pre-setting pressurization can effectively eliminate the excess air and voids within the fresh concrete, therefore enhancing the mechanical properties of the hardened concrete specimens of various types. Compared with non-pressurized specimens, the porosity values of pressurized specimens were reduced by 73.11% to 86.53%, the density values were increased by 1.43% to 8.31%, and the UCS values were increased by 8.42% to 187.43%. These findings provide a reference for using a continuous high pre-setting compression pressure and using CDG soil as an aggregate in the fabrication of concrete materials with improved mechanical performance.

Antimicrobial susceptibility testing data analysis over 3 years at the Yaoundé General Hospital, Cameroon.

Antimicrobial resistance (AMR) is a major health concern with high rates in low-income countries. Bacteriology laboratories sustain the fight against AMR by providing antibiotic susceptibility testing (AST) results to ensure appropriate therapies. These laboratories generate a lot of data, which are usually used for prospective interventions. Our study conducted in a lower-middle-income hospital setting aimed to describe the profile of bacteria isolated from the specimens received over 3 years, assess their susceptibility profile and identify potential gaps or area of improvement from the analysis of our data. Monthly data were retrieved from registers for all specimens received between January 2020 until December 2022. Data were compiled and analysed using the R and WHONET software. Out of 3582 specimens received, 797 were culture positive (22.3%). Escherichia coli and Klebsiella pneumoniae were frequently isolated (30.5% and 24.2%, respectively). AST results analysis showed high resistance of Gram-negative bacteria to penams and cephems, whereas low resistance was observed to carbapenems. Susceptibility to antibiotics based on the AWaRe antibiotic classification was variable. The bacteriological profile in the various types of specimen was established and rational information to design a therapeutic protocol adapted to our hospital setting was obtained. AST results may not only be used for prospective guidance for treatment, but rather cumulative data analysis can contribute to design effective antibiotic prescriptions and improve general practices at the laboratory. This is, however, dependent on a good record-keeping, standardization of practices and collaboration between clinicians and laboratory scientists.

Leak-before-Break (LBB)-Based Safety Verification of Reverse Cyclic Loading for 316L Stainless Steel: A Study Using Flat ESG Specimens

The leak-before-break design concept is based on J-R curves, which are obtained by J-R tests on various types of specimens and are known to be dependent on the cyclic load history. The J-R curves of standard specimens suggested by the American Society for Testing Materials are determined based on quasi-static tensile loading. However, seismic loading induces a reverse cyclic loading that alternately applies a tensile and a compressive load to nuclear plant piping. Therefore, it is very important to obtain the fracture toughness characteristics under reverse cyclic loading for the integrity estimation of nuclear plant piping. The objective of this paper is to study the effects of reverse cyclic loading on the fracture toughness characteristics of SA312 TP316L stainless steel, which is a nuclear plant piping material. J-R tests on a flat, equivalent stress gradient specimen with varying incremental displacement were carried out. The test results were reviewed by comparing the J-R test results under quasi-static loading. In addition, the safety margin of the nuclear plant piping was evaluated using a crack driving force diagram method. For the SA312 TP316L stainless steel, the results showed that the J-R curves were decreased with a decrease in the incremental displacement. When the incremental displacement was set to 0.25 mm, the unstable crack growth point value was about 73.0% of those for the quasi-static loading conditions.

Experimental Evaluation of Vibrational Stability of SOPs in Aerospace Industry Using PCB Strain Effectiveness of a PCB-Strain-Based Design Methodology

Steinberg’s theory, which is based on the fatigue failure theory, has been widely used for predicting the structural safety of solder joints in aerospace electronic units under vibration during launches. However, theoretical limitations are encountered when evaluating the structural safety of highly integrated electronic packages mounted on printed circuit boards (PCBs) under various boundary conditions. Therefore, in our previous study, a PCB-strain-based methodology was proposed to overcome the technical limitations of the conventional Steinberg theory, and its effectiveness was validated by conducting fatigue life tests on various types of specimens, such as the ball grid array, column grid array, and quad flat package. In this study, the aim was to increase its completeness and reliability by targeting small outline packages (SOPs) that have not yet been considered. The finite element (FE) model of the SOP was proposed to guarantee the reliable prediction of the structural safety of the solder joints used in the PCB-strain-based methodology. The proposed modeling technique contributes to enable the rapid construction of an FE model for the electronic unit because it was greatly simplified into a zero-dimensional lumped mass and rigid link element to simulate the package mass and solder joint, respectively. The effectiveness of the methodology was validated by performing fatigue life tests on PCB specimens under various boundary conditions. Those experimental and analytical results indicated that the proposed methodology was much more effective in predicting the structural safety of a solder joint for various cases of tested specimens compared with the Steinberg’s theory. The simplified FE model of SOP with the rigid link element connected to six points on the package mounting area of the PCB was effective for estimating margin of safety of solder joint. The results of this study would contribute to increase the availability of the proposed methodology for rapid mechanical design of electronic units in aerospace industries.

Biomarkers of Stress and Inflammation in Children.

Background: Children are increasingly exposed to stressors that can affect their immune function. Given the possible negative effects of stress and inflammation on health, researchers need to use appropriate biomarkers to measure both the effects of stress and subsequent inflammatory responses. Purpose: The purpose of this paper is to briefly review stress and inflammatory pathways, identify biomarkers used to measure chronic stress and chronic inflammation particularly in children in clinical and community settings, and to discuss methodological considerations when measuring stress and inflammation in children. Discussion: Biomarkers of chronic stress can be classified as central, meaning they are made in the brain, or peripheral, meaning they are made in the peripheral tissues in response to central signals. The peripheral biomarker, cortisol, is most frequently used in the community setting. In addition, indirect measures, such as oxytocin, may complement the assessment of stress. Common biomarkers of chronic inflammation in children are C-reactive protein (CRP), TNF-α, and IL-6. Similarly, indirect biomarkers of chronic inflammation, such as IL-2 and IL-1β, may also be considered. Conclusions: Various types of specimens can be used to measure these biomarkers of stress and inflammation including blood, saliva, urine, sweat, hair, nails, and tears. Each type of specimen has different requirements for collection, storage, and assay. Future research would benefit from standardized biomarker levels across age and development in children and incorporation of other biomarkers.

Pulsed infrared thermal imaging as inline quality assessment tool

Pulsed infrared thermography (PIRT) is a very fast and non-destructive technique for testing various types of specimens. This makes PIRT interesting for 100 %-inspections in industrial production lines. Especially for the die attach interface inspection of sintered and soldered electronic components and layer-to-layer interfaces in fiber-reinforced plastic (FRP), the industry is looking for alternatives to cost intensive X-ray methods and the time-consuming scanning acoustic microscopy (C-SAM). A big challenge to use the PIRT technology for inspections in industrial production lines is the low emissivity of the surface of the device under test (DUT). This work will present a PIRT system including a vacuum foil lamination setup to avoid the necessary spray coating of DUTs with low emissivity surfaces in failure analyses. This system can be used as inline quality assessment tool with an integrated technique to perform reliable component inspections on a wide range of different specimens.

'Annoying Requests': The Missionary Johann Michael Carl Hupe's Collecting In Borneo (1842-1847)

Sarawak’s first missionary was Johann Michael Carl Hupe (1818–1861), from the German town of Halle. After working in southern Borneo for several months, Hupe eventually travelled overland from the west to the north coast of Borneo, where he tried to establish a mission school in Kuching. It is hardly known that he was collecting cultural artefacts and natural science specimens of various types in the Pulopetak region (at present, the region about fifteen kilometres northeast of Kuala Kapuas, Kalimantan Tengah) and in Sarawak this early. Today, only a signboard at the old Courthouse in Kuching memorializes him and the site of his mission house. This paper attempts to highlight Hupe’s role as a source for European knowledge and images about Borneo drawing on archival material from the Francke Foundations in Halle. The focal point of the paper will be on the objects Hupe collected and dispatched to Halle. Many of them can still be found in the Kunst-und Naturalienkammer or Cabinet of Artefacts and Natural Curiosities, the museum collection of the Francke Foundations. Others were circulated and passed on in different ways within existing networks. By examining the collecting project of Hupe, it will be demonstrated that, even in the first half of the nineteenth century, interest in Borneo and knowledge of this remote island in European circles was substantial, which connected the island to scientific and cultural circuits, and even into Protestant homes, with the traffic of its objects.

Derivation of pancreatic acinar cell carcinoma cell line HS-1 as a patient-derived tumor organoid.

Acinar cell carcinoma (ACC) of the pancreas is a malignant tumor of the exocrine cell lineage with a poor prognosis. Due to its rare incidence and technical difficulties, few authentic human cell lines are currently available, hampering detailed investigations of ACC. Therefore, we applied the organoid culture technique to various types of specimens, such as bile, biopsy, and resected tumor, obtained from a single ACC patient. Despite the initial propagation, none of these organoids achieved long-term proliferation or tolerated cryopreservation, confirming the challenging nature of establishing ACC cell lines. Nevertheless, the biopsy-derived early passage organoid developed subcutaneous tumors in immunodeficient mice. The xenograft tumor histologically resembled the original tumor and gave rise to infinitely propagating organoids with solid features and high levels of trypsin secretion. Moreover, the organoid stained positive for carboxylic ester hydrolase, a specific ACC marker, but negative for the duct cell marker CD133 and the endocrine lineage marker synaptophysin. Hence, we concluded the derivation of a novel ACC cell line of the pure exocrine lineage, designated HS-1. Genomic analysis revealed extensive copy number alterations and mutations in EP400 in the original tumor, which were enriched in primary organoids. HS-1 displayed homozygous deletion of CDKN2A, which might underlie xenograft formation from organoids. Although resistant to standard cytotoxic agents, the cell line was highly sensitive to the proteasome inhibitor bortezomib, as revealed by an in vitro drug screen and in vivo validation. In summary, we document a novel ACC cell line, which could be useful for ACC studies in the future.

Distribution Analysis of Candida albicans according to Sex and Age in Clinical Specimen Testing for Sexually Transmitted Diseases.

The prevalence of candidiasis, a contagious disease with high morbidity and mortality, has sharply increased globally over the last two decades. Candida albicans can cause serious infections in patients with weak immunity and in recipients of prolonged antibiotic treatment. Consequently, rapid and accurate identification of species can play an important role in the treatment of candidiasis. Here, we investigated the positive rate and infection trend of Candida albicans according to age, specimen type, and sex using multiplex real-time polymerase chain reactionbased testing of samples collected for the diagnosis of sexually transmitted diseases in Korea between 2018 and 2020. When the type of specimen collected was a swab, the positive rate of Candida albicans was higher among younger women, and tended to decrease with age. Analysis of swab samples revealed higher positive rates than urinalysis. The reduction trend in positive rates by age was comparable between the overall samples and urine specimens. Among male patients, the positive rate did not differ substantially across the various types of specimens collected. Previous studies have shown a higher prevalence of non-albicans Candida species than Candida albicans in clinical specimens, and exclusion of the former from our analysis may be a limitation of this study. However, our findings contribute significantly to the literature because globally, there is a paucity of epidemiological studies using molecular techniques to detect Candida albicans in sexually transmitted disease test samples.

Distribution Analysis of Candida albicans according to Sex and Age in Clinical Specimen Testing for Sexually Transmitted Diseases.

The prevalence of candidiasis, a contagious disease with high morbidity and mortality, has sharply increased globally over the last two decades. Candida albicans can cause serious infections in patients with weak immunity and in recipients of prolonged antibiotic treatment. Consequently, rapid and accurate identification of species can play an important role in the treatment of candidiasis. Here, we investigated the positive rate and infection trend of Candida albicans according to age, specimen type, and sex using multiplex real-time polymerase chain reactionbased testing of samples collected for the diagnosis of sexually transmitted diseases in Korea between 2018 and 2020. When the type of specimen collected was a swab, the positive rate of Candida albicans was higher among younger women, and tended to decrease with age. Analysis of swab samples revealed higher positive rates than urinalysis. The reduction trend in positive rates by age was comparable between the overall samples and urine specimens. Among male patients, the positive rate did not differ substantially across the various types of specimens collected. Previous studies have shown a higher prevalence of non-albicans Candida species than Candida albicans in clinical specimens, and exclusion of the former from our analysis may be a limitation of this study. However, our findings contribute significantly to the literature because globally, there is a paucity of epidemiological studies using molecular techniques to detect Candida albicans in sexually transmitted disease test samples.

A study on resistance of asphalt concrete exposed to the effect of mycelial fungi

Introduction. In recent years, the issue of improving the quality and service life of road surfaces has been relevant in Russian and worldwide. The main reasons for the early destruction of road surfaces is the quality of individual components and the imperfect composition of asphalt concrete that has pre-set durability. The results of studies, characterizing changes in the roadway surface properties, are of practical value. In this case, we consider the surface hardness of asphalt concrete specimens of various types, subjected to microbiological destruction, which is the property to be studied. The purpose of the work is to study the microbiological resistance of various asphalt concretes, to select and substantiate methods for assessing the biological stability of asphalt concrete subjected to mycelial fungi.
 
 Materials and methods. Asphalt concrete specimens contain BND 60/90 bitumen that has the following characteristics: needle penetration depth 0.1 mm at 25 °С – 85; needle penetration depth 0.1 mm at 0 °С — 35; ring and ball softening point 0 °С — 48; extensibility — 83 cm; penetration index — 0.6. Mineral powder, glass cullet powder, and food flour are used as fillers. MP-1 inactivated mineral filler, made of carbonate rock, having the true and average density of 2.71 and 1.71 g/cm3, respectively, was also used. Glass powder was obtained by grinding the waste glass of JSC “Lisma”, Saransk. The chemical composition of glass waste is (in percent for weight): SiO2 — 68.75–72.90; Na2O — 11.9–16.7; K2O — 1.2–3.8; CaO — 5.0–6.0; BaO — 2.2–5.5; MgO — 3.2–3.8; Fe2SO4 — 0.1–0.12; Al2O3 — 1.0–1.5. Food flour was considered as an additive that serves as the nutritional medium for mycelial fungi. Some other components, added to the studied specimens of asphalt concrete, are discussed in the work. The studied property, or hardness, was identified using the Hoppler consistometer. Testing results are provided in the paper. Linear interpolation of experimental data was conducted to identify hardness at the intermediate points to rank the tested asphalt concrete, the standard error between the hardness curve during the exposure and the straight line for the same exposure points. The results of the proposed method are explained graphically using the experimental data. It is assumed that the smaller the root-mean-square error, the more resistant the corresponding composition of asphalt concrete to the effect of mycelial fungi.
 
 Results. As a result of the studies and the application of the proposed hardness control methods, the best compositions were identified in terms of resistance to the effects of mycelial fungi. Each group of specimens and compositions of asphalt concrete under study was broken down by their resistance to the effects of the external environment, or mycelial fungi.
 
 Conclusions. The results of this research project enable the authors to evaluate the quality of asphalt concrete compositions exposed to the biological environment. The proposed approach to assessing the quality of asphalt concrete compositions can be applied to other building materials and products subjected to certain aggressive media.

S2.2c Talaromycosis in HIV-negative patients: challenges and counter-measures

S2.2 Histoplasmosis and talaromycosis, September 21, 2022, 3:00 PM - 4:30 PM Talaromycosis is an infection caused by the thermally dimorphic fungus Talaromyces marneffei (T. marneffei). It is endemic in tropical countries of Asia and Southeast Asia and has recently been recognized far beyond the traditional endemic areas. Talaromycosis was thought to be exclusively associated with HIV infection. However, an increasing number of T. marneffei infections have been reported in non-HIV-infected patients. Although the incidence of talaromycosis in non-HIV-infected patients is ˂ 10%, the atypical presentation of this disease can lead to misdiagnosis, inappropriate treatment, and poor outcomes, in addition to tremendous burden and suffering for patients and their families. Screening for immunodeficiencies in patients with talaromycosis is crucial in clinically suspicious cases. Our cohort studies identified three major immunodeficiencies in non-HIV patients with talaromycosis: (1) 85.9% anti-interferon-γ autoantibodies, (2) primary immunodeficiency disorders, and (3) tumors. In disseminated talaromycosis, most patients present with fever, anemia, weight loss, respiratory symptoms, hepatosplenomegaly, lymphadenopathy, and osteolytic destruction and are often misdiagnosed as tuberculosis and other diseases. Localized talaromycosis, on the other hand, is usually manifested by ulcers or masses in the mouth, throat, and external genitalia. Although antigen screening is an effective approach for diagnosing talaromycosis in patients with advanced HIV disease, pathogen-based detection is still limited by atypical clinical presentation. Direct microscopic examination, mycological culture, and histopathology are the standard traditional diagnostic methods used to isolate T. marneffei from clinical specimens, however, due to time-consuming, it might lead to delay diagnosis. Metagenomic next-generation sequencing (mNGS) technology has shown promising results as a rapid, convenient method for detecting T. marneffei from various types of specimens, leading to correct diagnosis and appropriate treatment. Based on our current retrospective study, mNGS has been shown to be equivalent and possibly superior to conventional fungal culture in terms of speed and specificity in the diagnosis of talaromycosis. In terms of final clinical diagnosis, mNGS showed a high sensitivity of 97.22% compared with conventional culture (61.11%). Correction of underlying immunodeficiencies and early use of antifungal agents are important treatment strategies for talaromycosis. Currently, there is no optimal therapeutic regimen for the treatment of talaromycosis in this specific group of patients. Amphotericin B is the first line to initial antifungal treatment, other antifungal agents such as voriconazole have shown good efficacy against talaromycosis. We investigated the efficacy of voriconazole in the treatment of talaromycosis using population pharmacokinetics. C-reactive protein (CRP) was found to significantly affect voriconazole plasma concentrations. Optimization of initial dosing based on CRP levels may be useful to guide voriconazole dosing in clinical practice. The mortality rate in non-HIV talaromycosis is higher than in the HIV population, which may be due to the nonspecific and complex clinical manifestations. Failure to initiate antifungal treatment in a timely manner often results in poor prognosis and even death. The course of treatment is protracted, unclear, and depends on the immune status of the patient. Diagnosis and treatment of talaromycosis remain a challenge. Optimization of diagnostic tools and treatment regimens to ensure early detection and prompt antifungal treatment should be considered.

Adaptive total variation based autofocusing strategy in ptychography

In ptychography, the axial diffraction distance between specimen and detector is extremely important since the precision of this a prior parameter can strongly affect the quality of reconstruction. However, in experiments, applying a simple evaluation model for image quality assessment (IQA) will result in low accuracy with various specimens in the autofocusing methods. In this paper, we propose an autofocusing strategy with adaptive Lp-norm based total variation (TV) model, which achieves high accuracy of the convergence. It has been verified in optical experiments that our method is applicable to various types of specimens. Besides, the method can work efficiently and stably with poorly estimated specimen-detector distance.

Comparative Genomic Analyses Reveal Potential Factors Responsible for the ST6 Oxacillin-Resistant Staphylococcus lugdunensis Endemic in a Hospital.

Oxacillin-resistant Staphylococcus lugdunensis (ORSL) is considered a life-threatening isolate in healthcare settings. Among ORSL clones, ST6-SCCmec II strains are associated with an endemic spread in hospitals. We analyzed the complete genome of ORSL CGMH-SL118, a representative strain. Results revealed that this strain contained three MGEs (two prophages and one plasmid) other than the SCCmec II element, which showed remarkable differences in genome organization compared to the reference strains from NCBI. Eight multidrug-resistant genes were identified. All but blaZ were carried by MGEs, such as the SCCmec II element [mecA, ant (9)-Ia, and ermA] and the prophage φSPbeta [aac (6')-aph (2'), aph (3')-III, and ant (6)-Ia], indicating that MGEs carrying multidrug-resistant genes may be important for ST6 strains. The prophage φSPbeta contains sasX gene, which was responsible for the pathogenesis of Staphylococcus aureus. A phage-mediated resistant island containing fusB (SlRIfusB-118) was found near φSPbeta, which was highly homologous to type III SeRIfusB-5907 of Staphylococcus epidermidis. In contrast to previous studies, over 20% of ST6 isolates showed a fusidic acid-resistant phenotype, suggesting that phage-mediated intraspecies transmission of resistant islands may become an important issue for ST6 strains. Sixty-eight clinical isolates of ST6 Staphylococcus lugdunensis (50 OSSL, oxacillin-sensitive S. lugdunensis, and 18 ORSL, including CGMH-SL118) collected from various types of specimens in the hospital were studied. Among these isolates in this study, ORSL showed similar drug-resistant genes and phenotypes as CGMH-SL118. The comparative genomic analyses highlight the contribution of MGEs in the development and dissemination of antimicrobial resistance in ST6 strains, suggesting that resistance determinants and virulence factors encoded by MGEs provide a survival advantage for successful colonization and spread in healthcare settings.

Ultrasonic flaw detection spectrogram characterization of vermicular graphite cast iron engine cylinder head

The defects formed in the manufacture of the vermicular graphite cast iron engine cylinder head seriously affect the operation of the engine, which is necessary to detect. Ultrasonic testing is a non-destructive testing method that has the advantages of quick response, high resolution, and high security. In this paper, various types of specimens are prepared corresponding to different types of actual defects in the vermicular iron cylinder head. An ultrasonic A-scan system was built to test the specimens. The short-time Fourier transform, the continuous wavelet transform, the empirical wavelet transform, and the empirical modal decomposition were adopted to transform the signals into spectrograms which were further analyzed to reveal the inherent features of defects. The results show that the short-time Fourier transform can be used to distinguish all the common defects comparing to other methods. Comparing to the time-domain waveforms, the transformed spectrograms provide clear time-frequency distribution and highlight the inherent characteristics of the signal.

Numerical modeling of crack initiation and propagation processes in various specimen’s types using the GTN material damage model

Problematic. A combination of experimental and computational methods for studying the processes of crack initiation and propagation in various specimen’s types is used to determine the mechanical properties of materials, as well as to improve the accuracy of assessing the strength and durability of structural elements. Research objective. Determination of the parameters of the Gurson-Tvergaard-Needleman (GTN) material damage model based on the numerical modeling results of various specimen’s types under various types of loading for steel 22K using the finite element method. Realization technique. Using the finite element method, numerical modeling of the processes of cracks nucleation and propagation in cylindrical specimens under uniaxial tension, in Charpy specimens under dynamic loading, and also in CT specimens under quasi-static loading was carried out for steel 22K using the GTN material damage model. The results of research. By comparing the experimental and numerical results, the full set of GTN material model parameters for steel 22K was determined. The stress state in the crack tip area and the kinetics of its propagation in the material of various specimen’s types under static and dynamic loading were estimated. Conclusions. The GTN material damage model with the parameter values determined from experiments, can be used for numerical simulation of the processes of crack initiation and propagation both in specimens of various types under various loading types, and in structural elements.

Analysis of Nucleic Acid and Antibody Detection Results for SARS-CoV-2 Infection.

Real-time polymerase chain reaction (RT-PCR) of virus nucleic acid test (NAT) has become the standard method to diagnose severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, there are still many limitations, especially the problem of the high false negative rate. Therefore, the aim of this study was to investigate the positive rate of SARS-CoV-2 NAT and evaluate the diagnostic performance of SARS-CoV-2 IgM and IgG antibody detection in novel coronavirus infection. A total of 10309 suspected or high-risk cases of infection with SARS-CoV-2 in Wuhan Hubei, China, were tested for virus NAT by RT-PCR. Among those cases, 762 COVID-19 patients and 143 patients with non-COVID-19 who were tested for SARS-CoV-2 IgM and IgG during the NAT period were screened. The difference between the two test methods was analyzed using the chi-square test. The positive rate of 10309 cases was about 36% (95% CI: 33.39%-39.67%). SARS-CoV-2 was present in various types of specimens, and alveolar lavage fluid had the highest positive rate [52.38% (95% CI: 31.02-73.74)]. The clinical sensitivity of serum SARS-CoV-2 IgM and IgG was 77.17% (588/762) and 94.88% (723/762), respectively, and the clinical specificity was 93.71% (134/143) and 90.21% (129/143). The area under the curve (AUC) of SARS-CoV-2 IgG and combination of IgG with IgM were equally larger than IgM [0.973 (95% CI: 0.964-0.983) vs 0.930 (95% CI: 0.910-0.949)]. IgG antibody had the highest specificity [100.0% (95% CI: 100.00%-100.00%)] and sensitivity [94.0% (95% CI: 92.45%-95.55%)] when detected alone or in combination with IgM antibody. The total coincidence rate of SARS-CoV-2 antibodies detection and SARS-CoV-2 NAT for the diagnosis of SARS-CoV-2 infection was 92.04% (833/905). Among the 34 SARS-CoV-2 NAT-negative patients with clinical symptoms and CT imaging features, 29 (85.29%) patients were positive for SARS-CoV-2 IgM, and 31 (91.76%) were positive for IgG. SARS-CoV-2 NAT should be considered for many types of specimens, and the combined test of SARS-CoV-2 IgM and IgG can make up for the problem of missed NAT in COVID-19 patients.

Grossing and reporting of bone tumor specimens in surgical oncology: Rationale with current evidence and recent updates.

Primary bone tumors, including sarcomas, are rare tumors and require a multidisciplinary approach, including inputs from a radiologist, pathologist, medical oncologist, and surgical and radiation oncologist, for optimal management. Over the years, there has been a paradigm shift toward the treatment of bone sarcomas, from radical resections to conservative surgical procedures, to achieve improved clinical and functional outcomes. This has led to receiving and processing various types of specimens in orthopedic oncopathology. Grossing and reporting of bone tumors require expertise. This review focuses upon the types of biopsies, grossing techniques of various specimens in orthopedic oncology and reporting, with rationale and recommendations from pathologists, actively involved in reporting and pursuing a special interest in bone tumors, based on current evidence. Furthermore, there is a section on some of the updates in the diagnosis of bone tumors, based on the recent fifth edition of the World Health Organization classification of tumors of soft tissues and bone.

Quasi-static flattening energy absorption process on preformed circular tubes by numerical and experimental analyses

This article presents a novel method to improve energy absorption performance of thin-walled circular tubes under quasi-static lateral loading through the preforming process. Desirable investigations are carried out by experimental tests and numerical simulations. Firstly, simple circular tubes are shaped into four different types (P1–P4) of preformed specimens, using a semi–cylindrical Teflon die and various blade-shaped indenters with semi–cylindrical nose. Then, the preformed specimens are laterally compressed between two rigid platens to perform flattening tests and their mechanical behaviors are investigated during the lateral flattening experiments, based on viewpoint of energy absorption. Some experiments are carried out and due to the test limitations, numerical simulations are performed, using the ABAQUS/Explicit software. In the following, based on the finite element analysis, various preformed specimens with different geometrical characteristics are simulated to investigate influences of wall thickness, preformed type and internal spanof the specimen cross–section and also, effects of loading direction on energy absorption performance of the preformed specimens. Also, some simple circular tubes are flattened as the benchmark and results of four types of the preformed samples are compared with the corresponding benchmark. The obtained results illustrate that by shaping the simple circular tubes into the preformed specimen, a new hollow prismatic samples are produced that their energy absorption capability is 11.5 times of the corresponding value of the benchmark; consequently, the present article suggest the preformed specimens of various types instead of the corresponding simple circular tubes, as better energy absorber.