Defective Aggregation Research Articles

Synchronous amelioration of SnO2surface aggregation and buried layer defects by sodium salts for high-efficiency and stable perovskite solar cells

The inclusion of BCA molecules in SnO2improves film coverage of ETL, regulates energy level, increases electron transport and migration ability, and enhances crystallization of perovskite. Overall, PSCs fabricated in open-air achieve a champion efficiency of 20.24%.

CRISPR/Cas9-Induced Inactivation of the Autism-Risk Gene setd5 Leads to Social Impairments in Zebrafish.

Haploinsufficiency of the SETD5 gene, encoding a SET domain-containing histone methyltransferase, has been identified as a cause of intellectual disability and Autism Spectrum Disorder (ASD). Recently, the zebrafish has emerged as a valuable model to study neurodevelopmental disorders because of its genetic tractability, robust behavioral traits and amenability to high-throughput drug screening. To model human SETD5 haploinsufficiency, we generated zebrafish setd5 mutants using the CRISPR/Cas9 technology and characterized their morphological, behavioral and molecular phenotypes. According to our observation that setd5 is expressed in adult zebrafish brain, including those areas controlling social behavior, we found that setd5 heterozygous mutants exhibit defective aggregation and coordination abilities required for shoaling interactions, as well as indifference to social stimuli. Interestingly, impairment in social interest is rescued by risperidone, an antipsychotic drug used to treat behavioral traits in ASD individuals. The molecular analysis underscored the downregulation of genes encoding proteins involved in the synaptic structure and function in the adult brain, thus suggesting that brain hypo-connectivity could be responsible for the social impairments of setd5 mutant fishes. The zebrafish setd5 mutants display ASD-like features and are a promising setd5 haploinsufficiency model for drug screening aimed at reversing the behavioral phenotypes.

Proton irradiation-induced defect aggregation and metallic nanoparticles in CaF2 single-crystal

Proton irradiation induced-defects aggregation and metallic nanoparticles in single-crystal CaF2 was investigated by X ray diffraction (XRD), Raman spectroscopy and UV–Vis spectrophotometry. The structural reports reveal the degradation of material crystallinity after irradiation without amorphization, as a result of generated anion point defects (F- and H-center pairs). Particularly, Raman analysis reveals the colloids formation and even the increase of their size with increasing energy. While confirming this result, the optical measurements show an anticorrelation between the concentration of F-centers and Ca colloids with increasing proton fluence. The blue shift of the colloid band, observed at higher energies, indicates that larger colloids are formed at deeper penetration, resulting in the development of a compressive stress in material.

3D mesoscale analysis of concrete containing defect damages during different freeze-thaw cycles

The damage process of concrete containing air pore and aggregate gradation defects under freeze-thaw (FT) cycles was parametrically studied by an ABAQUS coupled thermo-mechanical mesoscale numerical analyses platform. It was a stochastic finite element model (SFEM) developed by Python script program. The effectiveness of mesoscale model was verified by comparing 96 concrete samples divided to 4 groups with air pore and aggregate defects exposed to 0 to 90 FT cycles. The damage function of concrete for FT cycles was described by Weibull distribution equations. The analyses showed that air pore defects had a significant impact on concrete mechanical characteristics under FT cycles. When FT cycle number (n) reached 90, the strength loss of specimens with no defect was about 37.5%. When air pore content was 5% with non-uniform grading of aggregate, the strength loss of specimen was 61.6%. This showed that FT cycle damage effect on concrete was obvious which was more prominent for higher values of n.

Hermansky-Pudlak Syndrome: Spectrum in Oman.

Hermansky-Pudlak syndrome (HPS) is a rare autosomal recessive disorder, characterized by oculocutaneous albinism, a hemorrhagic diathesis secondary to storage pool-deficient platelets, and in some patients' pulmonary fibrosis, granulomatous colitis, and immunodeficiency. To date, 11 different types of Hermansky-Pudlak syndrome were identified. HPS type 2 is distinctively characterized by severe neutropenia and recurrent sinopulmonary infections. HPS is more common in Puerto Rico, and this is the first report deciphering the genotypic spectrum of HPS in Oman. Between 2001 and 2021, 8 Omani cases with HPS (3 HPS type 2, 1 HPS type 3, and 4 HPS type 6) had been suspected clinically and confirmed through genetic mutation analysis. Patients had mild hemorrhagic phenotype, and variable platelet aggregation defects with different platelet agonists. All patients had characteristic eye manifestations. In addition, patients with HPS type 2 had severe neutropenia. Novel mutations in AP3B1(c.205-1G>C, c.12_13delTA (p.Asn4Lysfs*6) and HPS6 (c.19_20delCT (p. Leu7Alafs*168) were not reported in population variant databases. Diagnosis of HPS had markedly improved in Oman; however, increased clinician awareness is needed. A high index of suspicion and early referral for diagnosis and initiation of proper treatment might help improve outcomes.

The polyketide synthase StlA is involved in inducing aggregation in Polysphondylium violaceum.

In the social amoeba Dictyostelium discoideum, the polyketide MPBD (4-methyl-5-pentylbenzene-1,3-diol) regulates the gene expressions of cAMP signaling to make cells aggregation-competent and also induces spore maturation. The polyketide synthase StlA is responsible for MPBD biosynthesis in D. discoideum and appears to be conserved throughout the major groups of the social amoeba (Dictyostelia). In this study, we analyzed the function of StlA in Polysphondylium violaceum by identifying the gene sequence and creating the knockout mutants. We found that Pv-stlA- mutants had defects only in cell aggregation but not in spore maturation, indicating that the function of StlA in inducing spore maturation is species-specific. We also found that MPBD could rescue the aggregation defect in Pv-stlA- mutants whereas the mutants normally exhibited chemotaxis to their chemoattractant, glorin. Our data suggest that StlA is involved in inducing aggregation in P. violaceum by acting on signaling pathways other than chemotaxis in P. violaceum.

Visible radiophotoluminescence of colour centres in lithium fluoride: from lasers to versatile radiation sensors

The peculiar photoluminescence characteristics of radiation-induced colour centres in lithium fluoride (LiF), well known for applications in optically-pumped tuneable lasers and broad-band miniaturised light-emitting photonic devices operating at room-temperature, are under exploitation in passive imaging detectors and dosimeters based on visible radiophotoluminescence in LiF crystals and polycrystalline thin films. Their high intrinsic spatial resolution, wide dynamic range and large field of view, combined with easy handling, ambient-light operation and no development need, allow to successfully extend their use from X-ray imaging to proton-beam advanced diagnostics and dosimetry, even at those low dose values that are typical of hadrontherapy. After exposure, the latent images stored in LiF as local formations of F2 and F3 + aggregate defects are read with an optical fluorescence microscope under illumination in the blue spectral range. Their visible emission intensity was found to be linearly proportional to the dose over at least three orders of magnitude, so that bi-dimensional LiF solid-state dosimeters based on spectrally-integrated radiophotoluminescence reading can be envisaged. Taking advantage of the low thickness of LiF thin films, transversal proton beam dose mapping was demonstrated at low proton energies, even at high doses. Recent results and advances concerning LiF crystals and polycrystalline thin film characterisation in the linearity range are presented and discussed with the aim of highlighting challenges related to increasing the LiF film detector radiation sensitivity to both particles (protons) and photons (X-rays), although therapeutic dose values typical of clinical radiotherapy are still a big challenge.

Interface microstructure and bonding mechanisms of 7050 aluminum alloy thick plates produced by vacuum roll cladding

Vacuum roll cladding (VRC) based on friction stir welding (FSW) is applied to prepare aluminum alloy thick plates, and the effect of rolling reduction ratios (60%, 70%, 80%) on the microstructure and mechanical properties at the bonding interface of aluminum alloy clad plates are investigated. The results show that voids at the interface are gradually closed and the original interface finally disappears with the increase of rolling reduction ratios. There are 3 kinds of recrystallization mechanisms at the interface during hot rolling. The contributions to the healing of the interface are in the following order: geometric dynamic recrystallization (GDRX) > discontinuous dynamic recrystallization (DDRX) > continuous dynamic recrystallization (CDRX). At a rolling reduction ratio of 80%, GDRX characterized by the “pinch-off” of original grains mainly occurs at the interface, and no aggregation of defects and impurity elements is detected. The tensile shear strength and fracture displacement at the interface both reach the level of the matrix, which indicates that a good metallurgical bonding has been achieved at the interface. Therefore, the key to improving the interfacial healing quality is to break the interfacial oxide film and further induce recrystallization at the interface through a large rolling reduction ratio.

Generation of sidewall defects in InGaN/GaN blue micro-LEDs under forward-current stress

This work investigates the effect of current stress on InGaN/GaN multiple-quantum-well flip-chip blue micro light-emitting diodes (μ-LEDs) with a mesa size of 30 × 30 μm2 and describes the stress-related mechanisms: defect aggregation and generation, which cause the change in optoelectronic performance of μ-LEDs. A forward-current stress is applied at 75 A/cm2 (0.7 mA) for 200 h. The device performance degrades with increasing stress time except until 25 h. During the initial 25 h of aging, the light output power and the external quantum efficiency (EQE) increase due to the improved crystal quality caused by aggregation of point defects in the active region, which are supported by the ideality factor and the S-parameter. The high-resolution emission-microscope images reveal that the generation of point defects at mesa sidewalls rather than the active region is crucial in performance degradation. We highlight, in particular, that the aging test generates sidewall point defects even though the sidewalls were properly passivated by a thick SiO2 layer. The mechanisms of defect aggregation and generation due to aging are consistently described by the ideality factor, the S-parameter, and the EQE.

P809: MODULATION OF ARACHIDONIC ACID PATHWAY BY IBUPROFEN RESULTS IN COMPLETE HEMATOLOGICAL RESPONSE IN GHOSAL HEMATODIAPHYSEAL DYSPLASIA WITHOUT NEED FOR CORTICOSTEROID

Background: Ghosal hematodiaphyseal dysplasia (GHDD) is a rare autosomal recessive disorder characterized by pancytopenia and increased bone density of the long bones. First described in families of Indian and Middle Eastern descent, subsequent studies identified the genetic lesion in this disease as due to loss of function mutations in the TBXAS1 gene encoding thromboxane synthase, a key component of the arachidonic acid pathway responsible for the formation of thromboxane A2 from prostaglandin H2. As well as pancytopenia, laboratory features include platelet aggregation defects and increase in osteoblastic activity, the latter being the basis of increased bone density in patients with Ghosal syndrome. Simultaneously, loss of thromboxane synthase activity may be associated with shunting of prostaglandin precursors away from production of thromboxane into production of pro-inflammatory prostaglandins. This may be the mechanism responsible for the observed marrow suppression seen in these patients. We describe a 3 year old female of non-consanguineous parents of Filipino origin who presented with marked pancytopenia. Next Generation Sequencing bone marrow failure gene panel revealed a novel homozygous mutation in TBXAS1. Subsequent DXA scanning revealed increased bone mineral density consistent with the diagnosis (Z -score +2.4 for lumbar spine (L1-4)) although clinical sequelae of bony disease were not apparent. Aims: While multiple case reports document that these patients have hematological response to long term corticosteroid therapy, we hypothesized that inhibition of cyclooxygenase (COX) upstream of thromboxane synthase in the arachidonic acid pathway may be effective in this condition. Methods: Patient was treated with ibuprofen at regular therapeutic doses (approximately 30 mg/kg/24 hours daily initially) and serial full blood counts were monitored. Results: The patient exhibited a rapid and complete response to ibuprofen with normalization of full blood counts. The dose of ibuprofen was reduced to 10 mg/kg/day, and hematologic response is maintained on low dose after one year.The treatment is well tolerated with no side effects. Image:Summary/Conclusion: Treatment of GHDD with ibuprofen is a novel approach that offers clear potential benefits in comparison to the known adverse effects profile of long term corticosteroids. Bone density scan and markers are in process to ascertain the impact of this treatment on bone density, although this may take longer to show beneficial effects. The treatment was easily tolerated and well managed by the patient and family at home with minimum disruption to her quality of life.

Monodispersed ZnO nanoink and ultra-smooth large-area ZnO films for high performance and stable organic solar cells

In the organic solar cells (OSCs), zinc oxide nanoparticles (ZnO NPs) have been widely used to fabricate electron transporting layer (ETL). However, spontaneous aggregation of NPs and film surface defects are two issues that limit the application of ZnO NPs in the printed photovoltaics. To simultaneously solve the two problems, the ZnO nanoinks were modified with a 2-(2-methoxyethoxy) acetic acid (MEA) solution, in which a monodispersed nanoink was obtained, and no aggregation occurred after 18 months of storage at room temperature. Meanwhile, the ZnO:MEA ETL had fewer surface hydroxyl groups defects because of Lewis acid-base interactions. The monodispersibility and passivated surface defects ensured an ultra-smooth ZnO film, leading to an improved device performance, longer lifetime, and higher thickness tolerance. As a result, an efficiency of 15.84% was achieved for the 1 cm2 PM6:Y6 ZnO:MEA ETL-based OSCs, and the T 80 lifetime was also increased to 6600 h. The thickness of ZnO:MEA ETL could be increased to 225 nm with less performance degradation. ZnO:MEA NPs were dispersed well in alcohols with high boiling points, which ensured a high-quality slot-die coated film. The ZnO:MEA ETL also has a unique advantage in flexible organic OSCs, with enhanced bending resistance during 10000 times bending. These properties demonstrated the great potential of ZnO:MEA nanoinks in the printed electronics.

Sinhcaf-dependent histone deacetylation is essential for primordial germ cell specification.

Primordial germ cells (PGCs) are the progenitor cells that give rise to sperm and eggs. Sinhcaf is a recently identified subunit of the Sin3 histone deacetylase complex (SIN3A-HDAC). Here, we provide evidence that Sinhcaf-dependent histone deacetylation is essential for germ plasm aggregation and primordial germ cell specification. Specifically, maternal-zygotic sinhcaf zebrafish mutants exhibit germ plasm aggregation defects, decreased PGC abundance and male-biased sex ratio, which can be rescued by re-expressing sinhcaf. Overexpression of sinhcaf results in excess PGCs and a female-biased sex ratio. Sinhcaf binds to the promoter region of kif26ab. Loss of sinhcaf epigenetically switches off kif26ab expression by increasing histone 3 acetylation in the promoter region. Injection of kif26ab mRNA could partially rescue the germ plasm aggregation defects in sinhcaf mutant embryos. Taken together, we demonstrate a role of Sinhcaf in germ plasm aggregation and PGC specialization that is mediated by regulating the histone acetylation status of the kif26ab promoter to activate its transcription. Our findings provide novel insights into the function and regulatory mechanisms of Sinhcaf-mediated histone deacetylation in PGC specification.

Correlated KPFM and TERS imaging to elucidate defect-induced inhomogeneities in oxygen plasma treated 2D MoS2 nanosheets

Modulating physical and chemical properties of two-dimensional (2D) transition metal dichalcogenides (TMDCs) by defect engineering induced by oxygen plasma is actively pursued. In this work, exfoliated 2D MoS2 layers treated by medium power oxygen plasma for different times (0, 10, 20, 40, and 60 s) are investigated using Kelvin probe force microscopy and tip-enhanced Raman spectroscopy (TERS) besides micro-Raman and photoluminescence (PL) spectroscopy. Under oxygen plasma, defects (mono- and di-sulfur vacancies) and chemical oxidation are predominant from 0 (native defects) up to 40 s, while etching becomes dominant beyond 40 s for mono- (1L), bi- (2L), and tri- (3L) layer MoS2 with optimal defect density for four- (4L) and more layers. While Raman spectra exhibited lattice distortion (broadening of phonon bands) and surface oxidation by the presence of sub-stoichiometric molytrioxide MoO3 (i.e., MoO3–x or MoSxO2–x), the increased spectral weight of trions and quenching in PL spectra are observed with treatment time. The localized nanodomains (∼20–40 nm) and aggregated vacancies as nanovoids and intermixed MoS2/MoO3–x alloy are identified in near-field Raman spectra. The atomic force microscopy also showed defects aggregation, and Kelvin probe force microscopy revealed the work function (WF) increase from 4.98 to 5.56 eV, corroborating the existence of MoO3–x phase which enables doping and shift Fermi level. We also highlight the unique interaction between the gold substrate and the formed MoO3–x facilitating Mo6+ cation reduction to lower oxidation (i.e., Mo4+), thereby yielding intermediate oxidation states responsible for lower WF (ca. theoretical 6.3 eV for stoichiometric MoO3). Strong correlations among the work function and vibrational and optical responses are established while exploring the oxygen plasma-induced defects and changing the landscape on oxygen doping at the nanoscale with varying MoS2 layers, which are useful for heterogeneous electrocatalysis and applicable to other 2D-TMDCs.

Evaluation of novel coagulation and platelet function assays in patients with chronic kidney disease

BackgroundHemostasis evaluation in chronic kidney disease (CKD) is critical for optimal management of thrombotic and bleeding events. Standard coagulation screens are inadequate for predicting coagulopathy in CKD. ObjectiveTo evaluate hemostasis parameters in patients with different stages of CKD using novel coagulation assays. Patients/MethodsCross‐sectional study of 30 healthy controls (HC) and 120 CKD patients (10 Stage 2, 20 Stage 3, 20 Stage 4, 20 Stage 5 not requiring renal replacement therapy, 20 transplant, 10 newly started on hemodialysis [HD], 20 established on HD). Standard laboratory tests were performed in addition to rotational thromboelastometry (ROTEM), multiple electrode aggregometry (MEA), thrombin generation assays, D‐dimer, and markers of thrombogenesis (thrombin‐antithrombin [TAT]), fibrinolysis, and endothelial activation (intercellular adhesion molecule‐1 [ICAM‐1]). ResultsD‐dimer, TAT, and ICAM‐1 concentrations were significantly higher in patients with CKD than HC (P < .01). ROTEM maximum clot firmness was significantly higher in patients than in HC (P < .01). In CKD Stage 5 patients (pre‐HD and started HD) adenosine diphosphate and thrombin receptor activating peptide MEA tests were significantly lower than HC indicating platelet aggregation defect (P < .05). Multivariate analysis confirmed the direct effect of estimated glomerular filtration rate (eGFR) in the variance of ROTEM and MEA tests. Endogenous thrombin potential and peak thrombin were not statistically different between groups, but Stage 5 CKD patients had prolonged lag time (7.91 vs. 6.33, P < .001) and time to thrombin peak (10.8 vs. 9.5, P < .05) compared to HC. ConclusionsPatients with CKD exhibit features of concomitant hypercoagulability measured by ROTEM and platelet dysfunction measured with MEA. eGFR was an independent determinant of platelet dysfunction and hypercoagulability.

Rotational thromboelastometry in critical phase of dengue infection: Association with bleeding

BackgroundThe critical phase of dengue carries a high risk of bleeding. Associations of coagulation test parameters and the risk of bleeding in the critical phase is unclear. This study examines the association of rotational thromboelastometry (ROTEM delta and ROTEM platelet) with bleeding risk of patients with dengue in the critical phase. MethodsA total of 105 patients with confirmed dengue in the critical phase were recruited, with two subsequent prospective time point analyses of ROTEM parameters and platelet count within 24 and 48 hours from the onset of the critical phase. Conventional coagulation tests were performed only at the initial time point. ResultsTwenty of 105 patients developed bleeding after onset of the critical phase. Within the first 24 hours of critical‐phase onset, platelet count, coagulation tests, and ROTEM delta were unable to differentiate patients with bleeding manifestations from those without (P < .05). Area under the curve of thrombin receptor activating peptide‐6 assay of ROTEM platelet (TRAPTEM) discriminated patients with bleeding manifestations from those without, at a cutoff value of <12.5 Ω*min at a sensitivity and specificity of 73.7%, and 60.2%. In patients who developed bleeding, the maximum lysis of extrinsic pathway of ROTEM was significantly lower in patients with severe bleeding compared to those with mild to moderate bleeding. (4.3 ± 3.4% vs 9.4 ± 7.5%; P = .01). ConclusionAn association with bleeding manifestations and TRAPTEM suggest a potential role for defective platelet aggregation in the pathogenesis of bleeding in the critical phase of dengue.

Diamond-destructive mantle metasomatism: Evidence from the internal and external textures of diamonds and their nitrogen defects

Metasomatic processes modify the composition of the subcratonic lithospheric mantle and can either form or destroy diamonds. The composition of these metasomatic agents is uncertain and has been mostly deduced from chemical zonation and overprints recorded by associated mantle silicates. Diamonds experience partial dissolution (resorption) during their residence in the mantle due to mantle metasomatism and later during their ascent in kimberlite magma. Diamonds, enclosed inside mantle xenoliths during the whole duration of ascent in kimberlite magma, can preserve their pre-kimberlite surface features, which record the last diamond-destructive metasomatic event to have occurred in the mantle. The geometry of diamond dissolution features acquired during mantle storage can provide information about diamond-destructive metasomatic events in the mantle. Diamond samples recovered from inside mantle xenoliths are extremely rare and mostly limited to eclogitic lithology, which suggests that variable resistance of different mantle lithologies to disintegration in kimberlite magma may affect representativity of these sample. Here we use whole diamond populations from exploration parcels and apply our earlier developed set of criteria to distinguish between kimberlitic and pre-kimberlitic surface features on diamonds. The study used diamonds (<1 to 4.5 mm size) from eight kimberlites in three localities: Orapa cluster, Botswana (BK1, AK15, and AK1 kimberlites), Ekati Mine, Northwest Territories, Canada (Grizzly, Leslie, Koala, and Misery kimberlites), and Snap Lake kimberlite dyke, Northwest Territories, Canada. The host kimberlites cover seven different volcaniclastic and coherent kimberlite lithologies, and our previous studies demonstrated a correlation between the style of kimberlitic resorption on diamonds and the host kimberlite lithology for these samples. From the total of 3256 studied diamonds, we identified 534 diamonds with pre-kimberlite surface textures. These pre-kimberlite surface textures display six distinct types, which are present in all the studied diamond parcels regardless of their geographic locality and host kimberlite lithology. The relative proportions of these types depend on the geographic locality showing linkage to a specific mantle source. We examined the relationship between the surface features on diamonds, their growth patterns revealed in cathodoluminescence (CL) images, the content and aggregation of nitrogen defects using Fourier transform infrared spectroscopy (FTIR), and nitrogen content in specific growth zones of diamonds obtained using secondary ion mass spectrometry (SIMS) for 82 Ekati diamonds.Our data show that growth step-faces develop on diamonds with complex multi-crystal cores, whereas flat-faced octahedra with simple oscillatory-zoned growth patterns derive from single growth events. Initial stages of dissolution affecting only outer growth zones develop simple serrate laminae on diamonds, while more extensive dissolution exposes more complex growth zones developing various shapes of laminae and etch features (trigons and irregular asperities). The effect of internal growth patterns on dissolution features is more profound during pre-kimberlitic than kimberlite-related resorption likely due to the greater role of defects in diamond dissolution at mantle conditions.Comparison with the results of diamond dissolution experiments shows that metasomatism by C-O-H fluid is not destructive to diamond, while carbonate-silicate melt-driven metasomatism causes diamond dissolution. Continuous change in the silicate content of silicate‑carbonate melts and temperature variations within 200 °C can explain all pre-kimberlite dissolution features observed in this study. Similar pre-kimberlite dissolution features on diamonds from both the Zimbabwe and Slave cratons suggests that these metasomatic processes are widespread and affected the mantle below the eight studied kimberlites.

Rare missense variants in Tropomyosin‐4 (TPM4) are associated with platelet dysfunction, cytoskeletal defects, and excessive bleeding

BackgroundA significant challenge is faced for the genetic diagnosis of inherited platelet disorders in which candidate genetic variants can be found in more than 100 bleeding, thrombotic, and platelet disorder genes, especially within families in which there are both normal and low platelet counts. Genetic variants of unknown clinical significance (VUS) are found in a significant proportion of such patients in which functional studies are required to prove pathogenicity. ObjectiveTo identify the genetic cause in patients with a suspected platelet disorder and subsequently perform a detailed functional analysis of the candidate genetic variants found. MethodsGenetic and functional studies were undertaken in three patients in two unrelated families with a suspected platelet disorder and excessive bleeding. A targeted gene panel of previously known bleeding and platelet genes was used to identify plausible genetic variants. Deep platelet phenotyping was performed using platelet spreading analysis, transmission electron microscopy, immunofluorescence, and platelet function testing using lumiaggregometry and flow cytometry. ResultsWe report rare conserved missense variants (p.R182C and p.A183V) in TPM4 encoding tromomyosin‐4 in 3 patients. Deep platelet phenotyping studies revealed similar platelet function defects across the 3 patients including reduced platelet secretion, and aggregation and spreading defects suggesting that TPM4 missense variants impact platelet function and show a disordered pattern of tropomyosin staining. ConclusionsGenetic and functional TPM4 defects are reported making TPM4 a diagnostic grade tier 1 gene and highlights the importance of including TPM4 in diagnostic genetic screening for patients with significant bleeding and undiagnosed platelet disorders, particularly for those with a normal platelet count.

Molecular dynamic simulations of displacement cascades in tungsten and tungsten–rhenium alloys: Effects of grain boundary and/or σ phase

Transmutation rhenium (Re) produced in tungsten (W) neutron irradiation not only segregates and precipitates at grain boundaries (GBs) but also forms the σ-phase (WRe) in the bulk. In this study, using a molecular dynamics (MD) method, we conducted collision cascade simulations in W and W–Re alloys with 5 or 10 at% Re atoms containing a GB/σ-phase and systematically examined the effect of GB and the evolution of σ-phase. We find the interstitials in W-Re alloy are preferentially absorbed by the GB region such that the number of vacancies in the bulk region is higher in W–Re alloys than in W; the defect distribution is sensitive to the distance of primary knock-on atoms from the GB plane. Furthermore, similar to the tendency in the GB region, interstitials are preferentially absorbed by the σ-phase, and Re atoms tend to aggregate near the σ-phase region. The absorption of σ-phases and the GB region leads to a considerable defect aggregation, which provides suitable conditions for the regrowth of σ-phase structure during long-term evolution. The results provide a reference for understanding the GB structure and precipitations in the displacement cascades of W and W-based alloy materials.

Electrical properties of ZnO/&lt;inline-formula&gt;&lt;tex-math id="Z-20220101164636"&gt;\begin{document}${\boldsymbol{\beta}} $\end{document}&lt;/tex-math&gt;&lt;alternatives&gt;&lt;graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="2-20210635_Z-20220101164636.jpg"/&gt;&lt;graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="2-20210635_Z-20220101164636.png"/&gt;&lt;/alternatives&gt;&lt;/inline-formula&gt;-Bi&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; interfaces featuring aggregation defect under external electric fields

The safe operation of power equipment largely depends on the overvoltage protection level of the arrester. The ZnO varistors are widely used as the core components of the arresters in power systems because of the excellent nonlinear volt-ampere characteristics. In order to study the electrical properties of ZnO varistors under different external electric fields from the microstructure, the method of first-principles based on density functional theory (DFT) is used, and structure of ZnO/&lt;i&gt;β&lt;/i&gt;-Bi&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; interface containing zinc interstitial (Zn&lt;sub&gt;i&lt;/sub&gt;) and oxygen vacancy (V&lt;sub&gt;o&lt;/sub&gt;) defects is built. The results show that the V&lt;sub&gt;o&lt;/sub&gt; defect migrates after full relaxation. The Zn&lt;sub&gt;i&lt;/sub&gt; shifts to the interface under an external electric field. The interface energy increases rapidly after the electric field intensity has exceeded 0.1 V/Å, which means that the interaction force between the interfaces becomes larger, the distance between ZnO and &lt;i&gt;β&lt;/i&gt;-Bi&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; layers decreases, and the conductivity increases rapidly. The differential charge density, work function and Bader charge analysis method are used to calculate the barrier height at the interface, which proves that the built-in electric field is an important cause ingredient responsible for the non-linear volt-ampere characteristics of ZnO varistors. The effects of atomic orbital energy level, trap energy level and energy gap on the macroscopic conductivity of ZnO varistors are analyzed by using the method of density of states analysis. In this work are analyzed the different electrical parameters of the ZnO/&lt;i&gt;β&lt;/i&gt;-Bi&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; interface with aggregation defects by adjusting the intensity of the external electric field, and a new idea is provided for learning the electrical characteristics of ZnO varistors.

Phase-field simulation of void evolution in UO&lt;sub&gt;2&lt;/sub&gt; under applied stress

Owing to the migration and aggregation of point defects produced by cascade collision, a large number of cavities form easily during irradiation of the uranium dioxide (UO&lt;sub&gt;2&lt;/sub&gt;) that is an important nuclear fuel. In addition, cavities are also inevitably introduced into the ceramic fuel during sintering. Moreover, the creep strain and thermal strain, caused by the extreme environment of high temperature and strong irradiation, significantly increase the applied stress of nuclear fuel. Therefore, it is crucial to investigate the microstructure evolution of the cavities in UO&lt;sub&gt;2&lt;/sub&gt; fuel under applied stress. In this work, a phase-field model of void evolution in UO&lt;sub&gt;2&lt;/sub&gt; under applied stress is established. Firstly, the elastic equilibrium equation is solved by the perturbation-iterative method, and the stress distribution around a single void under applied stress is calculated. The results show that the stress concentration is observed at the edge of the void, and the simulated stress distribution is consistent with the theoretically analytical results. Then, the evolution processes of a single void under different applied stresses are simulated by the phase-field model. The results show that the growth rate of void increases with the augment of applied stress. Finally, the effect of applied stress on grain growth and void evolution in polycrystalline are also studied. The results show that the applied stress will accelerate the void growth. With the increase of the applied stress, the effect of the applied stress on accelerating the void evolution increases.