Nghiên cứu thiết lập khoảng giá trị tham chiếu cho các chỉ số Doppler động mạch phổi ở thai nhi có tăng trưởng bình thường
Tạp chí Phụ sản, 2021
Mục tiêu: Thiết lập khoảng giá trị tham chiếu cho các chỉ số Doppler động mạch phổi ở thai nhi có... more Mục tiêu: Thiết lập khoảng giá trị tham chiếu cho các chỉ số Doppler động mạch phổi ở thai nhi có tăng trưởng bình thường. Phương pháp: Nghiên cứu cắt ngang, tiến cứu, bao gồm 168 thai kỳ đơn thai có tuổi thai từ 28-40 tuần và tăng trưởng thai nhi bình thường. Khảo sát động mạch phổi chính của thai nhi bằng Doppler xung để đo các thông số sau: thời gian tăng tốc (AT), thời gian tống xuất (ET), tốc độ tối đa dòng chảy đạt được trong thì tâm thu (PSV), chỉ số xung (PI). Từ các phép đo, tính toán tỷ số AT/ET. Kết quả: Tuổi trung bình của thai phụ trong nghiên cứu này là 29,79 ± 5,47 tuổi. Tuổi thai trung bình và cân nặng trung bình lúc sinh của thai nhi lần lượt là 35,55 ± 2,73 tuần và 2547 ± 647 gram. Có sự tăng dần có ý nghĩa thống kê của các thông số PSV, AT, và tỷ số AT/ET theo tuổi thai. Trong khi đó, PI giảm dần theo tuổi thai và có ý nghĩa thống kê. Sự biến thiên ET không có ý nghĩa trong suốt thai kỳ. Kết luận: Một khoảng giá trị tham chiếu cho các thông số Doppler động mạch ph...
In this paper, via Newton polyhedra, we define and study symmetric matrix polynomials which are n... more In this paper, via Newton polyhedra, we define and study symmetric matrix polynomials which are nondegenerate at infinity. From this, we construct a class of (not necessarily compact) semialgebraic sets in R n such that for each set K in the class, we have the following two statements: (i) the space of symmetric matrix polynomials, whose eigenvalues are bounded on K, is described in terms of the Newton polyhedron corresponding to the generators of K (i.e., the matrix polynomials used to define K) and is generated by a finite set of matrix monomials; and (ii) a matrix version of Schmüdgen's Positivstellensätz holds: every matrix polynomial, whose eigenvalues are "strictly" positive and bounded on K, is contained in the preordering generated by the generators of K.
In this paper we discuss the global weak sharp minima property for vector optimization problems w... more In this paper we discuss the global weak sharp minima property for vector optimization problems with polynomial data. Exploiting the imposed polynomial structure together with tools of variational analysis and a quantitative version of Lojasiewicz's gradient inequality due to D'Acunto and Kurdyka, we establish the Hölder type global weak sharp minima with explicitly calculated exponents.
Several algorithms are presented for solving linear least squares problems; the basic tool is ort... more Several algorithms are presented for solving linear least squares problems; the basic tool is orthogonalization techniques. A highly accurate algorithm is presented for solving least squares problems with linear inequality constraints. A method is also given for finding the least squares solution when there is a quadratic constraint on the solution.
International Journal on Natural Language Computing, 2013
This paper introduces two important elements of our VNewsQA/ICT system: its semantic models of si... more This paper introduces two important elements of our VNewsQA/ICT system: its semantic models of simple Vietnamese sentences and its semantic processing mechanism. The VNewsQA/ICT is a Vietnamese based Question Answering system which has the ability to gather information from some Vietnamese news title forms on the ICTnews websites (http://www.ictnews.vn), instead of using a database or a knowledge base, to answer the related Vietnamese questions in the domain of information and communications technology.
We present C-Sibelia, a highly accurate and easy-to-use software tool for comparing two closely r... more We present C-Sibelia, a highly accurate and easy-to-use software tool for comparing two closely related bacterial genomes, which can be presented as either finished sequences or fragmented assemblies. C-Sibelia takes as input two FASTA files and produces: (1) a VCF file containing all identified single nucleotide variations and indels; (2) an XMFA file containing alignment information. The software also produces Circos diagrams visualizing high level genomic architecture for rearrangement analyses. C-Sibelia is a part of the Sibelia comparative genomics suite, which is freely available under the GNU GPL v.2 license at http://sourceforge.net/projects/sibelia-bio. C-Sibelia is compatible with Unix-like operating systems. A web-based version of the software is available at http://etool.me/software/csibelia.
Journal of Mineralogical and Petrological Sciences, 2008
Recent geological and petrological investigations of the metamorphic rocks from Vietnam revealed ... more Recent geological and petrological investigations of the metamorphic rocks from Vietnam revealed the following new evidences to understand the tectonic evolution of Southeast Asia; 1) findings of ultrahigh-T (~ 1000 °C) pelitic granulites, highto ultrahigh-P (~ 40 kbar) mafic metamorphic rocks and high-P/medium-T gneisses from the Kontum Massif, 2) eclogite and high-P granulite from the Song Ma suture zone, and 3) ultrahigh-T aluminous granulite from the Red River zone. These lines of evidence are strongly indicative of the highestmetamorphic conditions in each metamorphic terrane. Estimated P-T conditions and reaction textures from these rocks delineate a characteristic clockwise pressuretemperaturetime (P-Tt) path for each other. Based on the combination of P-T paths from these complexes, twostages of metamorphic field gradient are identified. An earlier M0-stage of high-P/T gradient is recognized, based on the peak-P conditions from the Kontum Massif and Song Ma suture zone. A later M1-stage of low-P/T gradient is also identified by linking the peak metamorphic conditions from the Kontum Massif, the Song Ma suture zone and the Red River zone. The former metamorphic field gradient could represent an early continental collision event and the latter would indicate a peak metamorphic stage caused by very high-T magmatic intrusion (asthenosphere upwelling) as a heat source of ultrahigh-T metamorphism. A simultaneous collision metamorphism throughout Vietnam should have taken place during the continental collision between Indochina and South China cratons, which led to the formation of Trans Vietnam Orogenic Belt.
Journal of Mathematical Analysis and Applications, 2014
f p) : R n → R p be a polynomial map. This paper studies the existence of the following global Ło... more f p) : R n → R p be a polynomial map. This paper studies the existence of the following global Łojasiewicz-type inequality F (x) α + F (x) β cd x, F −1 (0) for all x ∈ R n , for some constants c > 0, α > 0, and β > 0. We show that the above inequality holds if one of the following conditions is satisfied: (i) F is convenient and Khovanskii non-degenerate at infinity; (ii) F is convenient and non-degenerate at infinity; (iii) F is Mikhailov-Gindikin non-degenerate. Further, in cases (ii) and (iii), the exponents α and β can be determined explicitly.
In this paper, we consider the following initial-boundary value problem (1.1) utt− µ (t) uxx+ f (... more In this paper, we consider the following initial-boundary value problem (1.1) utt− µ (t) uxx+ f (u, ut)= F (x, t), 0< x< 1, 0< t< T,(1.2) µ (t) ux (0, t)= K0u (0, t)+ t∫ 0 k (t− s) u (0, s) ds+ g (t),(1.3)− µ (t) ux (1, t)= K1u (1, t)+ λ1| ut (1, t)| α− 2ut (1, t),(1.4) u (x, 0)= u0 (x), ut (x, 0)= u1 ...
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