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Purpose. The aim of this study is to construct a typical ore model for Pb-Zn ore range in Ban Lin – Phia Dam and to compare it with the existing ones. The model is constructed based on three main elements of the mineral generation process, such as formation environment, generated-ore fluid source, and deposited-ore mechanism. The obtained results are aimed at determining and predicting the resource of sedimentary exhalative (SEDEX) Pb-Zn ore deposit in Vietnam. Methods. To comprehend the characteristics of the SEDEX Pb-Zn ore deposits in the Ban Lin – Phia Dam area, we employ a combination of approaches that include mineralography to determine the composition and tectonic structure of rocks and ore, inclusion analysis to determine the temperature and inclusion composition, Pb isotopic analysis and stable S isotopic analysis to explore the environment and sources of ore-forming materials. Findings. The sedimentary exhalative (SEDEX) Pb-Zn ore deposit arises from the dissolution of metal-rich salt deposits due to heating at shallow depths (several kilometers). Subsequently, this fluid migrates through faults and fractures to preferred locations where galena and sphalerite precipitate alongside sedimentary basin deposition. Originality. SEDEX ore deposits have been extensively studied in various regions of the world. Although there are multiple theories regarding their origin, including explosion, biological debris accumulation, and surface replacement, each model has its own distinct advantages and limitations in explaining the genesis and development of SEDEX ore deposits. Practical implications. The acquired findings are intended to identify and predict the resources of sedimentary exhalative Pb-Zn ore deposits in Vietnam. [ABSTRACT FROM AUTHOR]

Hereditary breast cancer is an inherited genetic condition, mainly caused by BRCA1 and BRCA2 gene mutations. These genetic changes can increase the risks of breast and ovarian cancers in women, while prostate and breast cancers in men. Especially, mutations in either BRCA1 or BRCA2 genes take important roles in early-onset breast cancer. The present study focused on a 47-year-old Vietnamese woman with breast cancer by applying targeted next-generation sequencing technique. A novel BRCA1 gene mutation, namely NM_007294.3 (BRCA1): c.4998insA (p. Tyr1666Terfs), was identified both in this patient and in some of the members in her family proved the fact that the mutated genes passed down through generations. This change may exponentially initiate breast cancer risks and become a valuable marker for exact clinical prognosis and treatment.

The aim of this paper is to study co-prolongationsof central extensions. We construct the obstruction theory forco-prolongations and classify the equivalence classes of these by kernels of ahomomorphisms between 2-dimensional cohomology groups of groups.

The aim of this paper is to study the $( alpha, gamma)$-prolongation of central extensions. We obtain the obstruction theory for $( alpha, gamma)$-prolongations and classify $( alpha, gamma)$-prolongations thanks to low-dimensional cohomology groups of groups.

The development of flexible thermoelectric devices is gradually attracting increasing attention, particularly in the field of material design. In this study, we use first-principles calculations combined with Boltzmann equations to study the electronic and transport properties of Ag2S1−xSex, a key material with many important properties and extraordinary ductility, as well as a wide range of thermoelectric applications. The effect of Se alloying on the electronic structure of Ag2S and defect formation is investigated, and the role of alloying in increasing the n-type carrier concentration is discussed. The electron–phonon coupling approximation is used to reproduce the experimentally observed transport properties reasonably well, which shows that this scattering model is suitable for predicting the transport properties of semiconductors in thermoelectric applications. [ABSTRACT FROM AUTHOR]

Layered silicene with deformed buckled structure attracts great interest as a next generation 2D Dirac thermoelectric material beyond conventional layered materials. However, the difficulty of modulating atomic positions in silicene prevents its realization. This study proposes a method to deform buckled structure in layered silicene by controlling the intercalated atoms, which can dramatically enhance its thermoelectric properties. Silicene buckled structure is deformed in epitaxial CaSi2 thin films, Ca‐intercalated layered silicenes, on Si(111) substrates, which is related to the composition of intercalated Ca. Therein, buckling height of silicene is changed. This CaSi2 film with deformed silicene exhibits not only metal‐like electrical conductivity but also three times larger Seebeck coefficient than the theoretically predicted value, resulting in ≈3000 times larger power factor (≈40 μW cm−1 K−2) than that of the reported CaSi2 film at room temperature. This result experimentally demonstrates that power factor can be greatly enhanced by deforming the silicene buckled structure. [ABSTRACT FROM AUTHOR]

Background: Psychological distress is prevalent in patients with cancer, negatively affecting their treatment and quality of life. Clinical guidelines recommended screening all cancer patients routinely for psychological problems using simple measures such as the Distress Thermometer (DT) and Problem List (PL). This study is the first research in Vietnam to identify the optimal DT cutoff point to screen distress and the relationship with PL items among cancer patients. Methods: 300 cancer patients were recruited from 10 departments at Vietnam National Cancer Hospital (K hospital) and completed the DT and PL. Participants also completed the Patient Health Questionnaire‐9 (PHQ‐9) and the Generalized Anxiety Disorder‐7 (GAD‐7) with standard cutoff scores for identifying significant depression and anxiety. Results: Receiver operating characteristic (ROC) curve analyses showed that a DT cutoff score of 4 had an area under the ROC curve of 0.81 and 0.82 using the PHQ‐9 and GAD‐7 cutoff scores of 10 as the criterion, respectively. This indicated good overall accuracy. This cutoff also showed a sensitivity of 0.87 and 0.92 for PHQ‐9 and GAD‐7 total score defined cases, respectively. Both specificity values were 0.58. In terms of the PL, 164 distressed patients (54.7%) reported significantly more emotional problems, family issues, and practical and physical problem, implying various causes contribute to psychological distress among cancer patients. Conclusions: The study showed that the DT with a cutoff of 4 accompanied with PL is a simple and effective instrument compared to previous, longer measures commonly used to detect psychosocial distress in Vietnamese cancer patients. This cutoff point also identified patients with problems contributing towards distress. [ABSTRACT FROM AUTHOR]

In this paper, the electronic structure and transport properties of a ductile thermoelectric material α-Ag2S are examined using first-principles calculations combined with the Boltzmann transport equation within a constant relaxation-time approximation. The use of the exchange–correlation functional SCAN + rVV10 successfully describes the geometric and electronic structure of α-Ag2S with a direct bandgap value of 0.99 eV, which is consistent with the previous experimental observations. Based on the calculations of the formation energy of typical intrinsic defects, it is found that intrinsic defect formation greatly affects the conductivity of the system where silver vacancy and interstitial silver act as p-type and n-type defects, respectively. Large Seebeck coefficients at room-temperature, of around −760 μV K−1 for n-type and 1400 μV K−1 for p-type, are realized. It is also suggested that the doping of fully filled d-block elements such as Cu and Au not only maintained the Seebeck coefficients at high values but also improved electrical conductivity by more than 1.4 times, leading to the improvement of the power factor by up to 40% compared to the non-doped sample at low carrier concentration. [ABSTRACT FROM AUTHOR]

A new theoretical approach has been established to define transport coefficients of charge and mass transport in porous materials directly from impedance data; thus four transport coefficients could be determined. In case of ammonia adsorption on sulfated zirconia, the diffusion coefficient was figured out to be approximately the mobility diffusion coefficient of ammonium ions: 1.2 x 10-7 cm2/s. The transport of carbon dioxide was examined for samples of zeolite type 5A in different hydration states. By impedance spectroscopy measurements, the diffusion coefficient of water vapor at 373 K is estimated to be about 7 x 10-6 cm2/s. The influence of carbon dioxide adsorption on diffusion coefficients is studied based on two pellet types of zeolite 5A. The difference between polar and non-polar gas adsorption in porous solids is considered as changed characteristic of impedance. [ABSTRACT FROM AUTHOR]

Two versions of interatomic potentials for iron-carbon system based on the analytic bond-order potential formalism were developed and tested on diffusion of carbon in body-centered cubic (BCC) iron. By using these potentials, we found that carbon diffuses from octahedral site to the next nearest neighbor octahedral site via tetrahedral site, with energy barriers of 0.74 and 0.70 eV, respectively. These values are in good agreement with the transition from octahedral site to octahedral site via tetrahedral site with energy barriers of about 0.81–0.87 eV, observed in experiment. Other theoretical works found similar diffusion mechanism with energy barriers of about 0.72–0.92 eV. We also verified the transferability of the newly developed potential in the study of the effect of carbon on the body-centered cubic/face-centered cubic (BCC/FCC) phase transition in iron following the phase transition in the Bain mechanism. We found that the presence of carbon leads to the decrease of the BCC to FCC transformation energy barrier, consistent with first-principles calculations. Thus, the new potentials can be good candidates for modeling carbon diffusion and the transformation processes in iron-carbon alloys. [ABSTRACT FROM AUTHOR]

In this paper, we state the notion of morphisms in the category of abelian crossed modules and prove that this category is equivalent to the category of strict Picard categories and regular symmetric monoidal functors. The theory of obstructions for symmetric monoidal functors and symmetric cohomology groups are applied to show a treatment of the group extension problem of the type of an abelian crossed module. [ABSTRACT FROM AUTHOR]

The adsorption of nitric oxide (NO) on various metal phthalocyanines (MPc, M = Mn, Fe, Co) has been studied using first-principles calculations based on density functional theory (DFT). In this study, we investigated the fully optimized geometries and electronic structure of MPc. We found that the electronic structures of metal atoms are essential in shaping the ground-state electronic structure near the Fermi level. These states are defined mostly by the d orbitals of the transition-metal atoms and, to some degree, by the states of nitrogen and carbon atoms of the inner rings. The numerical calculations showed that NO strongly chemisorbs to the metal atom with an end-on configuration and results in a change in geometric and electronic structures of MPc. The N−O bond lengths are slightly longer than that of the isolated NO molecule. The orbital energy levels are shifted with respect to the Fermi level. The HOMO−LUMO gap widens as compared to bare MPc. These changes are attributed to the hybridization of the π* orbital of NO and the d orbitals of the transition metal. Specifically, the interaction between dπ and the π* orbital is significant for MnPc−NO, while the hybridization of dz2 and the π* orbital plays an important role in CoPc−NO. [ABSTRACT FROM AUTHOR]

Ann-category is called almost strict if its natural equivalences, except a natural equivalence of commutativity and of the distributivity, are identities. The purpose of this paper is to prove that every Ann-category is Ann-equivalent to an almost strict Ann-category of the type (R, M) and to give new interpretations of the cohomology groups H3 (R, M) of the rings R. The present paper consists, in a certain sense, of an extension of our results in [4-6]. Reading the present paper requires certain knowledge of the main results, which were announced in [3]. For completeness, we briefly recall some of the material that will be indispensable for the understanding of this paper. Throughout this paper, for the tensorial product of two objects A and B, we write AB instead of A ⊗ B, but for the morphisms we still write f ⊗ g to avoid confusion with composition. [ABSTRACT FROM AUTHOR]

Correction for 'Intrinsic defect formation and the effect of transition metal doping on transport properties in a ductile thermoelectric material α-Ag2S: a first-principles study' by Ho Ngoc Nam et al., Phys. Chem. Chem. Phys., 2021, DOI: 10.1039/d0cp06624a. [ABSTRACT FROM AUTHOR]

In complex structures such as conjugated Si nanoparticles on carbon nanotubes (CNT), new properties arise out particle size control or nanoparticle–nanotube contact. In this work, the interaction of Si clusters (Sin, n=1–4) with metallic (5,5) single-wall carbon nanotube (SWCNT) is investigated using first principles calculations based on density functional theory, to show that electronic property of the Si/SWCNT system can change via Si–SWCNT conformation alone. Planar Si clusters on SWCNT exhibit the same metallic property regardless of size. However, once the planarity of Sin is lost, which happens when Si adsorption sites shifts towards the top and the Si–C bonds bend resulting to a buckled Sin configuration, a band gap of ∼0.32 eV in the entire Si/SWCNT system is introduced. The migration behavior of Si adatoms shows ease of cluster formation due to surface curvature. Such cluster formation can be accommodated by a distortion in the C–C bonds of CNT. Mechanism for the opening of the SWCNT band gap is presented. [ABSTRACT FROM AUTHOR]

• The third layer As-antisite defect in GaAs(1 1 0) mimics that of bulk GaAs. • STM image from experiment and theory present a unique asymmetric two-lobe contrast. • Calculated LDOS and STS spectra reveal three prominent peaks as surface signatures. We reveal the As-antisite (As Ga) defect close to the surface of GaAs(1 1 0) with bulk characteristics using first-principles methods with experimental verifications. We found that the As Ga in the third-layer mimics the geometry, partial charge density and more importantly, the density of states of As Ga in bulk GaAs. Notably, the mid-gap state induced by As Ga in bulk GaAs is well-reproduced by the As Ga in the third layer of GaAs(1 1 0). Simulated and experimental STM images show an "asymmetric two-lobe" feature in the region around the defect. Using local density of states (LDOS) and STS spectra, we propose three prominent peaks with characteristic energy levels corresponding to the third layer As Ga. The above results present the first report of surface electronic signatures of true bulk defect near the surface of GaAs(1 1 0). [ABSTRACT FROM AUTHOR]

In this paper, the electronic structure and transport properties of a ductile thermoelectric material α-Ag2S are examined using first-principles calculations combined with the Boltzmann transport equation within a constant relaxation-time approximation. The use of the exchange-correlation functional SCAN + rVV10 successfully describes the geometric and electronic structure of α-Ag2S with a direct bandgap value of 0.99 eV, which is consistent with the previous experimental observations. Based on the calculations of the formation energy of typical intrinsic defects, it is found that intrinsic defect formation greatly affects the conductivity of the system where silver vacancy and interstitial silver act as p-type and n-type defects, respectively. Large Seebeck coefficients at room-temperature, of around -760 μV K-1 for n-type and 1400 μV K-1 for p-type, are realized. It is also suggested that the doping of fully filled d-block elements such as Cu and Au not only maintained the Seebeck coefficients at high values but also improved electrical conductivity by more than 1.4 times, leading to the improvement of the power factor by up to 40% compared to the non-doped sample at low carrier concentration.

Correction for 'Intrinsic defect formation and the effect of transition metal doping on transport properties in a ductile thermoelectric material α-Ag 2 S: a first-principles study' by Ho Ngoc Nam et al., Phys. Chem. Chem. Phys., 2021, DOI: .

Breast cancer is a heterogeneous disease with different tumor subtypes. Identifying risk categories will help make better treatment decisions. Hence, this study aimed to predict the survival outcomes of invasive breast cancer in Vietnam, using St Gallen 2007 classification. This study was conducted on 501 patients with breast cancer who had surgical operations, but had not received neoadjuvant chemotherapy, from 2011 to 2013. The clinicopathological characteristics were recorded. Immunohistochemistry staining was performed on ER, PR, HER2/neu, and Ki67 markers. For HER2/neu(2+), fluorescence in situ hybridization was used as the test. All patients with breast cancer were stratified according to 2007 St Gallen categories. Kaplan-Meier and log-rank models were used to analyze survival rates. There were 3.8% cases classified as low risk (LR), 72.1% as intermediate risk (IR1: 60.1% and IR2: 12.0%), and 24.1% as high risk (HR1: 11.8% and HR2: 12.3%). Patients who were LR had the best prognosis, with a 5-year overall survival (OS) rate of 100%. Intermediate-risk patients were at 92.3%. High-risk patients had the worst prognosis, with a 5-year OS proportion of 69.3% ( P < .05). For disease-free survival (DFS), risk categories were categorized as LR: 100%, IR: 90.3%, and HR: 69.3% ( P < .05). Three main risk categories of breast cancer had a distinct OS and DFS. These findings suggest that the 2007 St Gallen risk category could be used to stratify patients with breast cancer into different risk groups in Vietnam.

Purpose The global burden of cancer is slated to reach 21.4 million new cases in 2030 alone, and the majority of those cases occur in under-resourced settings. Formidable changes to health care delivery systems must occur to meet this demand. Although significant policy advances have been made and documented at the international level, less is known about the efforts to create national systems to combat cancer in such settings. Methods With case reports and data from authors who are clinicians and policymakers in three financially constrained countries in different regions of the world-Guatemala, Rwanda, and Vietnam, we examined cancer care programs to identify principles that lead to robust care delivery platforms as well as challenges faced in each setting. Results The findings demonstrate that successful programs derive from equitably constructed and durable interventions focused on advancement of local clinical capacity and the prioritization of geographic and financial accessibility. In addition, a committed local response to the increasing cancer burden facilitates engagement of partners who become vital catalysts for launching treatment cascades. Also, clinical education in each setting was buttressed by international expertise, which aided both professional development and retention of staff. Conclusion All three countries demonstrate that excellent cancer care can and should be provided to all, including those who are impoverished or marginalized, without acceptance of a double standard. In this article, we call on governments and program leaders to report on successes and challenges in their own settings to allow for informed progression toward the 2025 global policy goals.