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1.
Cell Mol Biol (Noisy-le-grand) ; 70(4): 134-139, 2024 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-38678619

RESUMEN

The purpose of this study was to explore the relationship between the MYCN gene, serum neuron-specific enolase (NSE), urinary vanillylmandelic acid (VMA) levels, and neuroblastoma pathological features and prognosis. Ninety-four children with neuroblastoma treated in the hospital were selected to compare the differences in MYCN gene amplification, serum NSE, and urinary VMA levels in children with different clinicopathological features and prognoses. The proportion of children with MYCN gene copy number ≥10 in INSS stage 3-4 was higher than that of children with INSS stage 1-2 (P < 0.05); the proportion of children with MYCN gene copy number ≥10 in high-risk children in the COG risk stratification was higher than that of children with intermediate and low risk (P < 0.05); the serum NSE of children aged >12 months higher than that of children aged ≤12 months (P < 0.05); serum NSE of children with tumors >500 cm3 higher than that of children with tumors ≤500 cm3 (P < 0.05); serum NSE and urinary VMA of children with INSS staging of stages 3-4 were higher than that of children with stages 1 to 2 (P < 0.05); serum NSE and urinary VMA in children with lymph node metastasis were higher than that of children without lymph node metastasis (P < 0.05); serum NSE of children with MYCN gene copy number ≥10 was higher than that of children without lymph node metastasis (P < 0.05); the proportion of children with MYCN gene copy number ≥10 who died, and the percentages of serum NSE and urinary VMA were higher than those of the surviving children (P < 0.05). MYCN gene amplification and serum NSE and urinary VMA levels were related to the age, tumor size, INSS stage, COG stage, lymph node metastasis, and prognosis of the children with neuroblastoma.


Asunto(s)
Proteína Proto-Oncogénica N-Myc , Neuroblastoma , Fosfopiruvato Hidratasa , Ácido Vanilmandélico , Humanos , Neuroblastoma/genética , Neuroblastoma/sangre , Neuroblastoma/orina , Neuroblastoma/patología , Proteína Proto-Oncogénica N-Myc/genética , Masculino , Femenino , Pronóstico , Lactante , Preescolar , Fosfopiruvato Hidratasa/sangre , Fosfopiruvato Hidratasa/genética , Fosfopiruvato Hidratasa/orina , Ácido Vanilmandélico/orina , Ácido Vanilmandélico/sangre , Estadificación de Neoplasias , Dosificación de Gen , Niño , Amplificación de Genes , Biomarcadores de Tumor/sangre , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/orina
2.
Fetal Pediatr Pathol ; 42(5): 815-819, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37655742

RESUMEN

Background: Neurogenic monodermal teratomas (NMTs) have been reported in the ovaries but not from bone. Case Report: A 6-year-old girl had an incidentally discovered lesion in the right scapula. Upon removal, it was an NMT with predominant choroid plexus. The disease had not progressed for 31 months. Conclusion: Neurogenic monodermal teratomas can also occur in bone.


Asunto(s)
Neoplasias Ováricas , Teratoma , Femenino , Niño , Humanos , Escápula , Teratoma/diagnóstico
3.
Cancer Control ; 30: 10732748231187837, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37575028

RESUMEN

OBJECTIVE: Recent therapeutic advances have greatly enhanced the survival rates of patients with neuroblastoma (NB). However, the outcomes of neuroblastoma patients in China, particularly those with high-risk (HR) NB, remain limited. METHOD: We retrospectively analyzed the clinical data and outcomes of NB patients who were treated at a tertiary pediatric cancer facility in China between January 2013 and October 2021. RESULTS: A total of 117 NB patients were recruited. Patients with very low-risk (VLR), low-risk (LR), intermediate-risk (IR), and HR-NB patients made up 4%, 27%, 15%, and 54% of total patient population, respectively. Patients diagnosed between 2013 and 2018 were treated according to the protocol of Sun Yat-Sen University Cancer Center and those diagnosed between 2019 and 2021 were treated according to the COG ANBL0531 or ANBL0532 protocol with or without autologous stem cell transplantation (ASCT). The 5-year EFS and OS of all risk groups of patients were 67.29% and 77.90%, respectively. EFS and OS were significantly decreased in patients with higher risk classifications (EFS: VLR/LR vs IR vs HR: 97.22% vs 67.28% vs 51.83%; ***P = .001; OS: VLR/LR vs IR vs HR: 97.06% vs 94.12% vs 64.38%; *P = .046). In HR-NB patients treated according to the COG protocol between 2019 and 2021, the 3-year OS of patients who received tandem ASCT was significantly greater than those who did not receive ASCT (93.33% % vs 47.41%; *P = .046; log-rank test). EFS was not significantly different between patients with and without ASCT (72.16% vs 60.32%). CONCLUSION: Our findings show that patients with lower risk classification have a positive prognosis for survival. The prognosis of patients with HR-NB remains in need of improvement. ASCT may enhance OS in HR-NB patients; however, protocol adjustment may be necessary to increase EFS in these patients.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Neuroblastoma , Niño , Humanos , Estudios Retrospectivos , Trasplante Autólogo , Neuroblastoma/terapia , Pronóstico , Resultado del Tratamiento , Supervivencia sin Enfermedad
4.
Front Genet ; 13: 954288, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36072668

RESUMEN

Background: Desert hedgehog (DHH), as a member of the Hedgehog (HH) family, is mainly involved in testicular development and peripheral nerve sheath formation. A DHH variant has been identified in patients with 46, XY gonadal dysgenesis (46, XY GD) with or without neuropathy, but few reports mention the involvement of other complications. Case presentation: Here, we report a Chinese female patient who was hospitalized at 14.3 years old due to slow breast development for more than 1 year. She had a female genitalia phenotype and breast development started at 13 years old but progressed slowly. She was not yet menarche on admission, and she had intermittent muscle cramps in her hands and feet. Her karyotype analysis was 46, XY and the SRY gene was positive. Surgical exploration revealed no uterus or ovaries, and the pathology of bilateral gonads was dysplastic testis tissue, which was consistent with partial gonadal dysgenesis (PGD). Genetic analysis identified a homozygous pathogenic variant in DHH exon 3 (c.1027T>C, p. Cys343Arg). During the 6-year follow-up, she received estrogen replacement therapy, resulting in breast development progression without gender dysphoria. However, her peripheral neuropathy became more obvious, and a nerve conduction study (NCS) indicated decreased nerve conduction velocity and action potential. In addition, she also suffered complications such as obesity, insulin resistance, fatty liver, and gastric ulcers. Conclusion: In the present study, we reported a case of 46, XY GD with minifascicular neuropathy caused by a DHH homozygous variant, and we summarized the reported cases worldwide. For the first time in such patients, we showed a comparison of NCS changes with age as well as the presence of multiple complications not previously reported.

5.
World J Gastroenterol ; 27(15): 1655-1663, 2021 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-33958850

RESUMEN

BACKGROUND: Gastrointestinal cytomegalovirus (CMV) disease occurs commonly in immunocompromised/immunodeficient patients with advanced human immunodeficiency virus infection, neoplasm, solid organ transplantation, hematopoietic stem cell transplantation, or treatment with immunosuppressants, but is rarely reported in association with measles infection. CASE SUMMARY: We describe a case of extensive gastrointestinal CMV disease secondary to measles infection in a 9-mo-old boy who presented with persistent fever and bloody diarrhea. His condition was improved after ganciclovir treatment. Serological analysis of CMV showed negative immunoglobulin (Ig) M and positive IgG. Blood CMV-DNA was 9.26 × 103 copies/mL. The diagnosis of gastrointestinal CMV disease was confirmed by histopathological findings of intranuclear and intracytoplasmic inclusions and Owl's eye inclusion. This case highlights the differential diagnosis and histopathological characteristics of gastrointestinal CMV infection and laboratory tests. CONCLUSION: Extensive gastrointestinal CMV lesions can be induced by the immune suppression secondary to measles infection. Rational, fast, and effective laboratory examinations are essential for suspected patients.


Asunto(s)
Infecciones por Citomegalovirus , Enfermedades Gastrointestinales , Sarampión , Citomegalovirus , Infecciones por Citomegalovirus/complicaciones , Infecciones por Citomegalovirus/diagnóstico , Infecciones por Citomegalovirus/tratamiento farmacológico , Ganciclovir/uso terapéutico , Humanos , Lactante , Sarampión/complicaciones , Sarampión/diagnóstico
6.
Phys Rev Lett ; 126(3): 037201, 2021 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-33543946

RESUMEN

Sr_{2}CuTeO_{6} is a square-lattice Néel antiferromagnet with superexchange between first-neighbor S=1/2 Cu spins mediated by plaquette centered Te ions. Substituting Te by W, the affected impurity plaquettes have predominantly second-neighbor interactions, thus causing local magnetic frustration. Here we report a study of Sr_{2}CuTe_{1-x}W_{x}O_{6} using neutron diffraction and µSR techniques, showing that the Néel order vanishes already at x=0.025±0.005. We explain this extreme order suppression using a two-dimensional Heisenberg spin model, demonstrating that a W-type impurity induces a deformation of the order parameter that decays with distance as 1/r^{2} at temperature T=0. The associated logarithmic singularity leads to loss of order for any x>0. Order for small x>0 and T>0 is induced by weak interplane couplings. In the nonmagnetic phase of Sr_{2}CuTe_{1-x}W_{x}O_{6}, the µSR relaxation rate exhibits quantum critical scaling with a large dynamic exponent, z≈3, consistent with a random-singlet state.

7.
Clinics (Sao Paulo) ; 76: e2126, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33503181

RESUMEN

OBJECTIVE: In our organization, it has been necessary in our organization to calculate the risk categories according to the American Thyroid Association (ATA), the American Association of Clinical Endocrinologists/American College of Endocrinology/Associazione Medici Endocrinologi (AACE/ACE/AME), and the American College of Radiology Thyroid Imaging Reporting and Data System (ACR TIRADS) classification systems for each patient, from the year 2019; these are also required to be registered in the database. This creates a barrier to medical collaboration in everyday radiological practice because using multiple rating systems can be confusing for both readers and patients. For the change in routine practice, this study aimed to compare diagnostic parameters of the ATA, AACE/ACE/AME, and ACR TIRADS classification systems for the detection of suspicious thyroid nodule(s) considering the results of fine-needle aspiration cytopathology as the reference standard. METHODS: Data on ultrasound characteristics (2,000 nodules) and fine-needle aspiration cytopathology (39 nodules) were included in the analysis. The decision making of fine-needle aspiration biopsies was evaluated from the ultrasound characteristics as per the ATA, AACE/ACE/AME, and ACR TIRADS classification systems. RESULTS: The ATA, AACE/ACE/AME, and ACR TIRADS recommended 26, 32, and 37 nodules for fine-needle aspiration biopsies, respectively. Considering the results of fine-needle aspiration cytopathology as the reference standard, the ATA, AACE/ACE/AME, and ACR TIRADS classification systems had 0.993, 0.996, and 0.998 sensitivity, respectively. The accuracies were 0.641, 0.795, and 0.923, respectively. CONCLUSION: The ACR TIRADS classification system is less invasive and can identify suspicious nodules more accurately than that of ATA and AACE/ACE/AME.


Asunto(s)
Neoplasias de la Tiroides , Nódulo Tiroideo , Biopsia con Aguja Fina , Estudios Transversales , Humanos , Neoplasias de la Tiroides/diagnóstico por imagen , Nódulo Tiroideo/diagnóstico por imagen , Ultrasonografía , Estados Unidos
8.
Braz J Med Biol Res ; 54(3): e9206, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33503202

RESUMEN

Renal fibrosis is one of the most significant pathological changes after ureteral obstruction. Transforming growth factor-ß (TGF-ß) signaling pathway plays essential roles in kidney fibrosis regulation. The aims of the present study were to investigate effects of microRNA-302b (miR-302b) on renal fibrosis, and interaction between miR-302b and TGF-ß signaling pathway in murine unilateral ureteral obstruction (UUO) model. Microarray dataset GSE42716 was downloaded by retrieving Gene Expression Omnibus database. In accordance with bioinformatics analysis results, miR-302b was significantly down-regulated in UUO mouse kidney tissue and TGF-ß1-treated HK-2 cells. Masson's trichrome staining showed that miR-302b mimics decreased renal fibrosis induced by UUO. The increased mRNA expression of collagen I and α-smooth muscle actin (α-SMA) and decreased expression of E-cadherin were reversed by miR-302b mimics. In addition, miR-302b up-regulation also inhibited TGF-ß1-induced epithelial mesenchymal transition (EMT) of HK-2 cells by restoring E-cadherin expression and decreasing α-SMA expression. miR-302b mimics suppressed both luciferase activity and protein expression of TGF-ßR2. However, miR-302b inhibitor increased TGF-ßR2 luciferase activity and protein expression. Meanwhile, miR-302b mimics inhibited TGF-ßR2 mRNA expression and decreased Smad2 and Smad3 phosphorylation in vivo and in vitro. Furthermore, over-expression of TGF-ßR2 restored the miR-302b-induced decrease of collagen I and α-SMA expression. In conclusion, this study demonstrated that miR-302b attenuated renal fibrosis by targeting TGF-ßR2 to suppress TGF-ß/Smad signaling activation. Our findings showed that elevating renal miR-302b levels may be a novel therapeutic strategy for preventing renal fibrosis.


Asunto(s)
Enfermedades Renales , MicroARNs/genética , Transducción de Señal , Proteínas Smad/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Obstrucción Ureteral , Animales , Línea Celular , Transición Epitelial-Mesenquimal , Fibrosis , Humanos , Riñón/patología , Enfermedades Renales/genética , Enfermedades Renales/patología , Ratones , Obstrucción Ureteral/patología
9.
Onco Targets Ther ; 14: 347-353, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33469311

RESUMEN

Here, we report a rare case of a 12-year-old boy who was initially diagnosed with B cell lymphoblastic lymphoma (BLBL) and developed myeloid sarcoma (MS) eight months after chemotherapy. Next-generation sequencing (NGS) showed mutations of KRAS and NRAS genes in both the bone marrow and lymph node. He presented an abnormal karyotype of 46, XY, -9, der (16) t (9; 16) (q13; q12), +mar. He received chemotherapy according to the South China Children's Leukemia Group 2016 protocol. Complete remission was achieved by the 15th day post-treatment. Eight months later and immediately prior to the start of maintenance therapy, the patient developed fever, skin nodules in both upper arms, and enlargement of bilateral testes. Pathological analysis of skin and testicular biopsies suggested the diagnosis of myeloid sarcoma (MS). Again, NGS examination showed mutations of KRAS and NRAS genes. The patient underwent haploidentical hematopoietic stem cell transplantation but unfortunately did not survive. The interval of eight-month interval between the initial disease onset and MS brings into question whether MS developed as part of the initial onset of disease or as a secondary tumor in association with chemotherapy. Thus, understanding the pathogenesis of MS involving abnormalities of lymphoid progenitors may assist in the prediction of prognosis and development of novel target therapies.

10.
Braz. j. med. biol. res ; 54(3): e9206, 2021. graf
Artículo en Inglés | LILACS | ID: biblio-1153519

RESUMEN

Renal fibrosis is one of the most significant pathological changes after ureteral obstruction. Transforming growth factor-β (TGF-β) signaling pathway plays essential roles in kidney fibrosis regulation. The aims of the present study were to investigate effects of microRNA-302b (miR-302b) on renal fibrosis, and interaction between miR-302b and TGF-β signaling pathway in murine unilateral ureteral obstruction (UUO) model. Microarray dataset GSE42716 was downloaded by retrieving Gene Expression Omnibus database. In accordance with bioinformatics analysis results, miR-302b was significantly down-regulated in UUO mouse kidney tissue and TGF-β1-treated HK-2 cells. Masson's trichrome staining showed that miR-302b mimics decreased renal fibrosis induced by UUO. The increased mRNA expression of collagen I and α-smooth muscle actin (α-SMA) and decreased expression of E-cadherin were reversed by miR-302b mimics. In addition, miR-302b up-regulation also inhibited TGF-β1-induced epithelial mesenchymal transition (EMT) of HK-2 cells by restoring E-cadherin expression and decreasing α-SMA expression. miR-302b mimics suppressed both luciferase activity and protein expression of TGF-βR2. However, miR-302b inhibitor increased TGF-βR2 luciferase activity and protein expression. Meanwhile, miR-302b mimics inhibited TGF-βR2 mRNA expression and decreased Smad2 and Smad3 phosphorylation in vivo and in vitro. Furthermore, over-expression of TGF-βR2 restored the miR-302b-induced decrease of collagen I and α-SMA expression. In conclusion, this study demonstrated that miR-302b attenuated renal fibrosis by targeting TGF-βR2 to suppress TGF-β/Smad signaling activation. Our findings showed that elevating renal miR-302b levels may be a novel therapeutic strategy for preventing renal fibrosis.


Asunto(s)
Humanos , Animales , Ratas , Obstrucción Ureteral/patología , Transducción de Señal , Factor de Crecimiento Transformador beta/metabolismo , MicroARNs/genética , Proteínas Smad , Enfermedades Renales/genética , Fibrosis , Línea Celular , Transición Epitelial-Mesenquimal , Riñón/patología , Enfermedades Renales/patología
11.
Clinics ; 76: e2126, 2021. tab, graf
Artículo en Inglés | LILACS | ID: biblio-1153950

RESUMEN

OBJECTIVE: In our organization, it has been necessary in our organization to calculate the risk categories according to the American Thyroid Association (ATA), the American Association of Clinical Endocrinologists/American College of Endocrinology/Associazione Medici Endocrinologi (AACE/ACE/AME), and the American College of Radiology Thyroid Imaging Reporting and Data System (ACR TIRADS) classification systems for each patient, from the year 2019; these are also required to be registered in the database. This creates a barrier to medical collaboration in everyday radiological practice because using multiple rating systems can be confusing for both readers and patients. For the change in routine practice, this study aimed to compare diagnostic parameters of the ATA, AACE/ACE/AME, and ACR TIRADS classification systems for the detection of suspicious thyroid nodule(s) considering the results of fine-needle aspiration cytopathology as the reference standard. METHODS: Data on ultrasound characteristics (2,000 nodules) and fine-needle aspiration cytopathology (39 nodules) were included in the analysis. The decision making of fine-needle aspiration biopsies was evaluated from the ultrasound characteristics as per the ATA, AACE/ACE/AME, and ACR TIRADS classification systems. RESULTS: The ATA, AACE/ACE/AME, and ACR TIRADS recommended 26, 32, and 37 nodules for fine-needle aspiration biopsies, respectively. Considering the results of fine-needle aspiration cytopathology as the reference standard, the ATA, AACE/ACE/AME, and ACR TIRADS classification systems had 0.993, 0.996, and 0.998 sensitivity, respectively. The accuracies were 0.641, 0.795, and 0.923, respectively. CONCLUSION: The ACR TIRADS classification system is less invasive and can identify suspicious nodules more accurately than that of ATA and AACE/ACE/AME.


Asunto(s)
Humanos , Neoplasias de la Tiroides/diagnóstico por imagen , Nódulo Tiroideo/diagnóstico por imagen , Estados Unidos , Estudios Transversales , Ultrasonografía , Biopsia con Aguja Fina
13.
Hum Cell ; 33(1): 159-174, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31713817

RESUMEN

Temozolomide (TMZ) is one of the most common drugs selected for glioma chemotherapy, but the therapeutic effect of glioma treatment is usually limited due to its resistance. Long non-coding RNA (lncRNA) is gradually found to be a vital regulator in numerous physiological and pathological processes. Lately, it was revealed that LINC00174 could promote CRC cell growth. However, the function and potential regulatory manner of LINC00174 in glioma remain unclear. Our results demonstrated that the expression level of LINC00174 was higher in glioma tissues, and LINC00174 down-regulation could remarkably prevent cell proliferation and promote cell apoptosis in both glioma cells and TMZ-resistant glioma cells. Mechanistic studies revealed that LINC00174 can sponge microRNA-138-5p (miR-138-5p) and down-regulate its expression, thereby up-regulating the protein level of miR-138-5p's target, sex-determining region Y (SRY)-box9 protein (SOX9). Additionally, in vivo experiments revealed that LINC00174 shRNA can serve as a tumor suppressor through down-regulating SOX9 in glioma. In this study, a novel established regulatory way of LINC00174/miR-138-5p/SOX9 axis was systematically studied, which may provide a new manner for glioma therapy.


Asunto(s)
Neoplasias Encefálicas/genética , Glioma/genética , MicroARNs/genética , Factor de Transcripción SOX9/genética , Temozolomida , Resistencia a Antineoplásicos/genética , Humanos
14.
Front Pharmacol ; 10: 1447, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31866865

RESUMEN

Background and Objective: Intravenous contrast-enhanced ultrasound (CEUS), using the second-generation ultrasound contrast agent SonoVue®, has been widely used in adults. In 2016, it was approved for pediatric applications by the American Food and Drug Administration (FDA). However, it has not been approved by the Chinese Food and Drug Administration (CFDA). The objective of the study was to evaluate the safety and effectiveness of CEUS in children prospectively at a single center in China. Methods: A total of 312 cases of Chinese children were enrolled in clinical trials. Contrast agent was given intravenously with two different doses, including 2.4 ml/time and 0.03 ml/kg. All CEUS was performed for evaluating adverse effect and the diagnostic accuracy compared with the pathology and enhanced CT. Results: All 312 subjects underwent CEUS successfully. The dose of contrast agent for CEUS was 2.4 ml between November 2015 and June 2016, which was modified to 0.03 ml/kg between July 2016 and April 2019, according to the recommendation of the FDA. With the two different doses of the contrast agent, the heart rate, respiration rate, oxygen saturation, and blood pressure of the participants had no statistically significant difference (P > 0.05) before and after administration. The blood pressure had been significantly decreased in participants who received combined anesthetic administration. Following 600 intravenous injections of the CEUS, there were three cases of transient rash and three cases of hypotension (n = 6, 1.92%). The six recovered quickly after receiving intravenous methylprednisolone and epinephrine. Most of the studies were performed for evaluating renal microcirculation and assisting renal biopsy (192/312 [61.5%]), which together had a 98.9% effectiveness in the identification of pathology in the specimens. Some studies were conducted to identify a mass in the liver, retroperitoneum, abdominal cavity, kidneys, testicles, thyroid, and so on (99/312 [31.4%]), which had a 97.6% accuracy. The other studies were conducted to identify trauma, vascular malformation, infection, hemorrhage, and so on (21/312 [6.73%]), which had a similar accuracy to enhanced CT. Conclusion: The adverse effects of CEUS in children are similar to that in adults. The results indicate that it is safe to use SonoVue® for CEUS in pediatric patients.

15.
Science ; 365(6460): 1418-1424, 2019 09 27.
Artículo en Inglés | MEDLINE | ID: mdl-31604269

RESUMEN

Thermoelectric technology allows conversion between heat and electricity. Many good thermoelectric materials contain rare or toxic elements, so developing low-cost and high-performance thermoelectric materials is warranted. Here, we report the temperature-dependent interplay of three separate electronic bands in hole-doped tin sulfide (SnS) crystals. This behavior leads to synergistic optimization between effective mass (m*) and carrier mobility (µ) and can be boosted through introducing selenium (Se). This enhanced the power factor from ~30 to ~53 microwatts per centimeter per square kelvin (µW cm-1 K-2 at 300 K), while lowering the thermal conductivity after Se alloying. As a result, we obtained a maximum figure of merit ZT (ZT max) of ~1.6 at 873 K and an average ZT (ZT ave) of ~1.25 at 300 to 873 K in SnS0.91Se0.09 crystals. Our strategy for band manipulation offers a different route for optimizing thermoelectric performance. The high-performance SnS crystals represent an important step toward low-cost, Earth-abundant, and environmentally friendly thermoelectrics.

16.
J Mol Model ; 25(8): 213, 2019 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-31280371

RESUMEN

Molecular dynamics (MD) simulation was conducted to research the effect of molar ratios for α/ß-HMX, γ/ß-HMX, and δ/ß-HMX(octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) mixture systems on thermal stability, sensitivity, and mechanical properties of explosives, and the computing models were established by Materials Studio (MS). The binding energies, the maximum trigger bond length (LN-NO2), cohesive energy density as well as mechanical properties of the mixture systems and the pure ß-HMX crystal were obtained and contrasted. The results demonstrate that the molar ratios have great influence on the binding capacity of molecules between α, γ, δ-HMX, and ß-HMX in the mixture systems. The binding energies decrease with the increase of molecular molar ratio and have the maximum values at the 1:1 M ratio. The maximum trigger bond length does not change apparently after mixing, while the cohesive energy density (CED) increases as the molar ratio increases but are all smaller than the pure ß-HMX crystal, demonstrating that the sensitivity of the mixture systems increases. The mechanical properties decrease after mixture, which illustrates that the mechanical properties of the pure crystal are superior to the mixture systems.

17.
BMC Pediatr ; 19(1): 143, 2019 05 06.
Artículo en Inglés | MEDLINE | ID: mdl-31060547

RESUMEN

BACKGROUND: The aim of this study was to review the growth data, gonadal function and tumour risk of children and adolescents with 45,X/46,XY mosaicism who presented to a single centre in China. METHODS: We conducted a retrospective review of the records of 32 patients with 45,X/46,XY mosaicism or variants who were hospitalized from August 2005 to September 2018. The main outcomes measured were growth data, genital phenotype, gonadal function, gonadal position, and histological results. RESULTS: A total of 32 patients were included. The age at diagnosis ranged from 0.6 to 16.3 years. Nineteen patients exhibited ambiguous genitalia, 12 had short stature, and 1 showed a lack of breast development. Seventeen patients were raised as males, and 15 were raised as females. The external masculinisation score (EMS) of patients raised as male was 4.5 (1~12) [median (range)]. The EMS of the females was 0 (0~1.5) [median (range)]. Patients showed normal heights under 2 years old, with a height SDS of 0 (- 1.5~1.4) [median (range)]. Growth appeared to decelerate after age 2 years, with SDS decreased to - 2.8 (- 3.0~ - 0.9) [median (range)]. The percentage of short stature was higher in females than in males (76.9% vs 50.0%). Twenty-five patients had gonadal pathological results. Complete gonadal dysgenesis (CGD) and mixed gonadal dysgenesis (MGD) were the most common pathogenic subtypes, accounting for 48.0 and 36.0%, respectively. Ovotesticular tissue was observed in only 4.0% of patients. Gonadoblastoma and positive OCT3/4 results were found in 18.8% of gonads in children over 2 years of age. Palpable gonads accounted for 50% of these. All patients who had gonadoblastoma were raised as females. CONCLUSIONS: Patients with 45,X/46,XY might have normal heights until 2 years old. Growth decelerations after 2 years of age were common. Patients who are being raised as females seemed to be shorter than males. CGD and MGD were the most common gonadal pathogenic subtypes. The tumour risk is high in these patients, even in palpable gonads and female patients.


Asunto(s)
Estatura/genética , Desarrollo Infantil/fisiología , Disgenesia Gonadal 46 XY/genética , Disgenesia Gonadal Mixta/genética , Neoplasias/genética , Síndrome de Turner/diagnóstico , Adolescente , Biopsia con Aguja , Niño , Preescolar , China , Estudios de Cohortes , Femenino , Hospitales Pediátricos , Humanos , Inmunohistoquímica , Masculino , Mosaicismo , Neoplasias/epidemiología , Fenotipo , Estudios Retrospectivos , Medición de Riesgo , Factores Sexuales , Síndrome de Turner/genética
18.
J Am Chem Soc ; 141(14): 5645-5649, 2019 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-30908017

RESUMEN

The dynamic behaviors of a new type of three-dimensional (3D) water framework symbiotic with 1D stacking organic guests, including an order-disorder transition of hydrogen atoms, a supercooling phenomenon during phase transition, and a dipole-glass-like relaxation behavior due to locally trapped water molecules, are presented. This extremely scarce 3D water framework, together with the rich dynamic behaviors it exhibits, provides new clues to design new ice-like models for promoting the fundamental understanding of the dynamic behavior of water in diverse solid-states.

19.
Phys Rev Lett ; 122(3): 037001, 2019 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-30735415

RESUMEN

We have systematically studied physical properties of Ba(Fe_{0.97}Cr_{0.03})_{2}(As_{1-x}P_{x})_{2}, where superconductivity in BaFe_{2}(As_{1-x}P_{x})_{2} is fully suppressed by just 3% of Cr substitution of Fe. A quantum critical point is revealed at x∼0.42, where non-Fermi-liquid behaviors similar to those in BaFe_{2}(As_{1-x}P_{x})_{2} are observed. Neutron diffraction and inelastic neutron scattering measurements suggest that the quantum critical point is associated with the antiferromagnetic order, which is not of conventional spin-density-wave type as evidenced by the ω/T scaling of spin excitations. On the other hand, no divergence of low-temperature nematic susceptibility is observed when x is decreased to 0.42 from higher doping level, demonstrating that there are no nematic quantum critical fluctuations. Our results suggest that non-Fermi-liquid behaviors in iron-based superconductors can be solely resulted from the antiferromagnetic quantum critical fluctuations, which cast doubts on the role of nematic fluctuations played in the normal-state properties in iron-based superconductors.

20.
BMC Genomics ; 20(1): 136, 2019 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-30767761

RESUMEN

BACKGROUND: Potassium (K) is essential to plant growth and development. Foxtail millet (Setaria italic L.) is an important fodder grain crop in arid and semi-arid regions of Asia and Africa because of its strong tolerance to drought and barren stresses. The molecular mechanisms of physiological and biochemical responses and regulations to various abiotic stresses such as low potassium conditions in foxtail millet are not fully understood, which hinders the research and exploitation of this valuable resource. RESULTS: In this research, we demonstrated that the millet variety Longgu 25 was the most insensitive variety to low potassium stress among other five varieties. The transcriptome analysis of Longgu 25 variety revealed a total of 26,192 and 26,849 genes from the K+-deficient and normal transcriptomic libraries by RNA-seq, respectively. A total of 1982 differentially expressed genes (DEGs) were identified including 866 up-regulated genes and 1116 down-regulated genes. We conducted a comparative analysis of these DEGs under low-K+ stress conditions and discovered 248 common DEGs for potassium deprivation among foxtail millet, rice and Arabidopsis. Further Gene Ontology (GO) enrichment analysis identified a series of candidate genes that may involve in K+-deficient response and in intersection of molecular functions among foxtail millet, rice and Arabidopsis. The expression profiles of randomly selected 18 candidate genes were confirmed as true DEGs with RT-qPCR. Furthermore, one of the 18 DEGs, SiMYB3, is specifically expressed only in the millet under low-K+ stress conditions. Overexpression of SiMYB3 promoted the main root elongation and improved K+ deficiency tolerance in transgenic Arabidopsis plants. The fresh weight of the transgenic plants was higher, the primary root length was longer and the root surface-area was larger than those of control plants after K+ deficiency treatments. CONCLUSIONS: This study provides a global view of transcriptomic resources relevant to the K+-deficient tolerance in foxtail millet, and shows that SiMYB3 is a valuable genetic resource for the improvement of K+ deficiency tolerance in foxtail millet.


Asunto(s)
Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Proteínas de Plantas/fisiología , Potasio/metabolismo , Setaria (Planta)/genética , Setaria (Planta)/metabolismo , Estrés Fisiológico/genética , Factores de Transcripción/fisiología , Arabidopsis/genética , Bases de Datos Genéticas , Perfilación de la Expresión Génica , Variación Genética , Ensayos Analíticos de Alto Rendimiento , Oryza/genética , Fenotipo , Proteínas de Plantas/genética , Raíces de Plantas/crecimiento & desarrollo , Plantas Modificadas Genéticamente/genética , Plantones/genética , Factores de Transcripción/genética
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