Bis-thiobarbiturate derivatives 1-15 have been synthesized, characterized by 1HNMR and El-MS and screened for urease inhibition. All compounds showed various degree of urease inhibitory activity with iC50 values rangi...Bis-thiobarbiturate derivatives 1-15 have been synthesized, characterized by 1HNMR and El-MS and screened for urease inhibition. All compounds showed various degree of urease inhibitory activity with iC50 values ranging 7.45 ± 0.12 - 74.24 ± 0.81 μmol/L while the standard thiourea behaved normally （ICso = 21.10 ±0.12）. Compounds I （IC50= 7.45 ± 0.12 ]μmol/L）, 9 （IC50 =18,17 ± 1.03 bmol/L） and 13 （IC50= 8.61 ± 0.45 bmol/L） showed excellent urease inhibitory activity in the series. Molecular modeling studies were performed to understand the binding site with the bimetallic nickel center of the enzyme. Structure-activity relationship has also been established for these compounds. This study identified bis- thiobarbiturate as a novel class of urease inhibitors.展开更多
A new series of benzothiazole Schiff bases 3–29 was synthesized and screened for antitumor activity against cervical cancer（Hela） and kidney fibroblast cancer（COS-7） cell lines. Results indicated that compounds 3...A new series of benzothiazole Schiff bases 3–29 was synthesized and screened for antitumor activity against cervical cancer（Hela） and kidney fibroblast cancer（COS-7） cell lines. Results indicated that compounds 3, 14, 19, 27 and 28 have promising activity against Hela cell line with IC50 values of 2.41,3.06, 6.46, 2.22 and 6.25 mmol/L, respectively, in comparison to doxorubicin as a reference antitumor agent（IC50 2.05 mmol/L）. In addition, compound 3 displayed excellent activity against COS-7 cell line with IC50 value of 4.31 mmol/L in comparison to doxorubicin（IC50 3.04 mmol/L）. In the present work,structure based pharmacophore mapping, molecular docking, protein-ligand interaction, fingerprints and binding energy calculations were employed in a virtual screening strategy to identify the interaction between the compounds and the active site of the putative target, EGFR tyrosine kinase. Molecular properties, toxicity, drug-likeness, and drug score profiles of compounds 3, 14, 19, 27, 28 and 29 were also assessed.展开更多
Adsorption-desorption kinetics of CO and H_2 on Ni surface were studied with molecular beam relaxation spectrometry. It is found that there are two adsorbed states in the substrate temperature range 330K<T<480K ...Adsorption-desorption kinetics of CO and H_2 on Ni surface were studied with molecular beam relaxation spectrometry. It is found that there are two adsorbed states in the substrate temperature range 330K<T<480K and 720K<T<900K respectively for CO/Ni system. These results can be explained by a precursor state model. Their kinetic parameters: E_(aα)=14.6kJ/mol, E_(dx)=49.3kJ/mol; E_(aβ)= 68.6kJ/mol, E_(dβ)=200.6kJ/mol. It is shown that there are two adsorbed states in the low (350K<T<430K) and high (550K<T<625K) temperature range respectively for H_2/Ni system. These results can be explained by a direct dissociative model. Their kinetic parameters:E_(dl)=26.3kJ/mol, E_(dh)=103.7kJ/mol.展开更多
Here some steady-state experiments on oxidation of CO on Pd were performed on a molecular beam apparatus. It is found that the characteristics of the rate of CO_2 formation r versus substrate temperature T are depende...Here some steady-state experiments on oxidation of CO on Pd were performed on a molecular beam apparatus. It is found that the characteristics of the rate of CO_2 formation r versus substrate temperature T are dependent on the ratio P=P_(CO)/P_(O2) in the mixed beam. These characteristics are related to the complicated interactions of co-adsorbed CO and O particles on Pd surface.展开更多
Molecular testing in thyroid nodules and thyroid cancer is rapidly evolving;care must be used when incorporating molecular testing for thyroid nodules into clinical practice. A clear appreciation of the goals and rest...Molecular testing in thyroid nodules and thyroid cancer is rapidly evolving;care must be used when incorporating molecular testing for thyroid nodules into clinical practice. A clear appreciation of the goals and restraints of molecular testing must be integrated into how physicians use and explain molecular testing to patients. Molecular tests can help rule in cancer for indeterminate thyroid nodules with very specific mutations for thyroid cancer, such as BRAF and RET/PTC, and can help reduce the rates of completion thyroidectomies in this era of de-escalation of the management of thyroid disease. The positive predictive value (PPV) of malignant cytology (Bethesda VI) is 98%;and even though molecular testing improves specificity and PPV, it falls short of this ideal for other mutations. We present a detailed evaluation of the current state of molecular testing and their clinical relevance in the setting of diagnostic utility and their impact on surgical decision-making. By recapitulating the clinical impact of these tests and some of the related drawbacks, we hope to provide adequate up to date information of the appropriate utilization of these tools in the management of indeterminate or suspicious thyroid nodules and highlight future directions on their utilization for the management of thyroid cancer.展开更多
Mechanical properties of high-entropy alloys(HEAs)with the face-centered cubic(fcc)structure strongly depend on their initial grain orientations.However,the orientation-dependent mechanical responses and the underlyin...Mechanical properties of high-entropy alloys(HEAs)with the face-centered cubic(fcc)structure strongly depend on their initial grain orientations.However,the orientation-dependent mechanical responses and the underlying plastic fl ow mechanisms of such alloys are not yet well understood.Here,deformation of the equiatomic FeMnCoCrNi HEA with various initial orientations under uniaxial tensile testing has been studied by using atomistic simulations,showing the results consistent with the recent experiments on fcc HEAs.The quantitative analysis of the activated deformation modes shows that the initiation of stacking faults is the main plastic deformation mechanism for the crystals initially oriented with[001],[111],and[112],and the total dislocation densities in these crystals are higher than that with the[110]and[123]orientations.Stacking faults,twinning,and hcp-martensitic transformation jointly promote the plastic deformation of the[110]orientation,and twinning in this crystal is more significant than that with other orientations.Deformation in the crystal oriented with[123]is dominated by the hcp-martensite transformation.Comparison of the mechanical behaviors in the FeMnCoCrNi alloy and the conventional materials,i.e.Cu and Fe50Ni50,has shown that dislocation slip tends to be activated more readily in the HEA.This is attributed to the larger lattice distortion in the HEA than the low-entropy materials,leading to the lower critical stress for dislocation nucleation and elastic–plastic transition in the former.In addition,the FeMnCoCrNi HEA with the larger lattice distortion leads to an enhanced capacity of storing dislocations.However,for the[001]-oriented HEA in which dislocation slip and stacking fault are the dominant deformation mechanisms,the limited deformation modes activated are insu fficient to improve the work hardening ability of the material.展开更多
Objective: To study the treatment of B-Thalas-semia (ThE) with Chinese herbal medicine for Bushen Yisui (BSYS), its theoretical base and molecular mechanism. Methods: Seventy-eight patients with ThE were treated with ...Objective: To study the treatment of B-Thalas-semia (ThE) with Chinese herbal medicine for Bushen Yisui (BSYS), its theoretical base and molecular mechanism. Methods: Seventy-eight patients with ThE were treated with BSYS recipe (consisted of 11 Chinese herbal drugs as Dogwood fruit, Fleeceflower root, prepared Rehmannia root and turtle shell, etc.) orally taken, 3 times per day, 10 g/time, 3 months as one therapeutic course. Hemoglobin (Hb), red blood cell (RBC), reticulocyte (Ret) and hemoglobin F (HbF) were checked every month. At the same time, PAGE, PVR, PCR-SSCP, RT-PCR, DNA series analysis, mRNA gene expression analysis techniques were used to conduct the systematic gene analysis in patients to study the molecular mechanism of TCM treatment from aspects of gene mutation, gene expression and control-regulation. Results: All the blood criteria in patients after BSYS treatment were improved significantly with clinical symptoms展开更多
Molecular dynamics simulations are carried out in order to Study the atomic structure of crystalline component of nanocrystalline α-Fe when it is consolidated from small grains. A two-dimensional computational block ...Molecular dynamics simulations are carried out in order to Study the atomic structure of crystalline component of nanocrystalline α-Fe when it is consolidated from small grains. A two-dimensional computational block is used to simulate the consolidation process. All the preset dislocations in the original grains glide out of them in the consolidation process, but new dislocations can generate when the grain size is large enough. It shows that dislocations exist in the consolidated material rather than in the original grains. Whether dislocations exist in the crystalline component of the resultant model nano-material depends upon grain size. The critical value of grain size for dislocation generation appears to be about 9 nm. This result agrees with experiments qualitatively.展开更多
A computer program has been developed for the moIlcular dynamics calculation of ionic orstrong-ionic covalent systems. Ewald summation algorithm and Keating potentiaI model areadopted to calculate the long-range Coulo...A computer program has been developed for the moIlcular dynamics calculation of ionic orstrong-ionic covalent systems. Ewald summation algorithm and Keating potentiaI model areadopted to calculate the long-range Coulomb interaction and the short-range bonding forces,respectively. A theoretical study on the domain boundary structures in epitaxial wurtzite GaN film is accomplished with the program. The calculation result is used in the structure formationexplanation of an interesting defect observed by HREM experiment.展开更多
The localized molecular orbitals for typical bowl-shaped circulenes are obtained by the use of INDO-LMO method. It is found that these bowl-shaped circulenes with strained π-electron systems are still aromatic and th...The localized molecular orbitals for typical bowl-shaped circulenes are obtained by the use of INDO-LMO method. It is found that these bowl-shaped circulenes with strained π-electron systems are still aromatic and the rim π-bonds with larger localization form reactive regions for formation of buckminsterfullerene.展开更多
Molecular dynamics simulations are performed to study the nanoindentation models of monolayer suspended graphene and graphyne. Fullerenes are selected as indenters. Our results show that Young＇s modulus of monolayer-...Molecular dynamics simulations are performed to study the nanoindentation models of monolayer suspended graphene and graphyne. Fullerenes are selected as indenters. Our results show that Young＇s modulus of monolayer-thick graphyne is almost half of that of graphene, which is estimated to be 0.50 TPa. The mechanical properties of graphene and graphyne are different in the presence of strain. A pre-tension has an important effect on the mechanical properties of a membrane. Both the pre-tension and Young＇s modulus plots demonstrate index behavior. The toughness of graphyne is stronger than that of graphene due to Young＇s modulus magnitude. Young＇s moduli of graphene and graphyne are almost independent of the size ratio of indenter to membrane.展开更多
We perform molecular beam epitaxy growth and scanning tunneling microscopy study of copper diselenide （CuSe2 ） films on SrTiO3 （001）. Using a Se-rich condition, the single-phase pyrite CuSe2 grows in the Stranski-...We perform molecular beam epitaxy growth and scanning tunneling microscopy study of copper diselenide （CuSe2 ） films on SrTiO3 （001）. Using a Se-rich condition, the single-phase pyrite CuSe2 grows in the Stranski-Krastanov （layer-plus-island） mode with a preferential orientation of （111）. Our careful inspection of both the as-grown and post-annealed CuSe2 films at various temperatures invariably shows a Cu-terminated surface, which, depending on the annealing temperature, reconstructs into two distinct structures 2 ×√3 and √x ×√3-R30°. The Cu termi- nation is supported by the depressed density of states near the Fermi level, measured by in-situ low temperature scanning tunneling spectroscopy. Our study helps understand the preparation and surface chemistry of transition metal pyrite dichalcogenides thin films.展开更多
Photoinhibition occurs when crops grow under strong light and are simultaneously subjected to stresses such as high or low temperature, drought,etc. It causes a decrease of crop photosynthetic efficiency leading to an...Photoinhibition occurs when crops grow under strong light and are simultaneously subjected to stresses such as high or low temperature, drought,etc. It causes a decrease of crop photosynthetic efficiency leading to an obvious decrease of the yield.展开更多
The term thyroid neoplasm incorporates tumors that originate from follicular cells and those that arise from parafollicular cells (C cells). Differentiated thyroid cancer, which originates from follicular cells, inclu...The term thyroid neoplasm incorporates tumors that originate from follicular cells and those that arise from parafollicular cells (C cells). Differentiated thyroid cancer, which originates from follicular cells, includes papillary thyroid carcinoma (PTC), follicular thyroid carcinoma (FTC), oncocytic cell carcinoma (Hürthle), poorly differentiated carcinoma, and anaplastic thyroid carcinoma (ATC). PTC tends to have an indolent clinical course with low morbidity and mortality. However, this entity has a broad range of biological and clinical behavior that can result in disease recurrence and death, depending on patient and tumor characteristics and the initial treatment approach. PTC is the most common form of well-differentiated thyroid cancer (WDTC) and based on the most recent statistics, accounts for approximately 89.4% of all thyroid malignancies. PTC appears as an irregular solid or cystic nodule in normal thyroid parenchyma. PTC has the propensity for lymphatic invasion, but it is less likely to have hematogenous spread. Around 11% of patients with PTC present with distant metastases outside the neck and mediastinum. This manuscript with review the current understanding of the epidemiology, pathology, molecular characteristics, prognostic factors, and dynamic risk stratification of PTC centered on an evidence-based and personalized approach.展开更多
The surface plasmon resonance(SPR)biosensor technology is a novel optical analysis method for studying intermolecular interactions.Owing to in-depth research on traditional Chinese medicine(TCM)in recent years,compreh...The surface plasmon resonance(SPR)biosensor technology is a novel optical analysis method for studying intermolecular interactions.Owing to in-depth research on traditional Chinese medicine(TCM)in recent years,comprehensive and specific identification of components and target interactions has become key yet difficult tasks.SPR has gradually been used to analyze the active components of TCM owing to its high sensitivity,strong exclusivity,large flux,and real-time monitoring capabilities.This review sought to briefly introduce the active components of TCM and the principle of SPR,and provide historical and new insights into the application of SPR in the analysis of the active components of TCM.展开更多
Among the structurally diverse NNRTIs, pyridinone scaffolds demonstrate high potency against HIV-1 wild type and drug-resistant strains. During the optimization of our pyridinone compound 1（LAM-trans）, we found that...Among the structurally diverse NNRTIs, pyridinone scaffolds demonstrate high potency against HIV-1 wild type and drug-resistant strains. During the optimization of our pyridinone compound 1（LAM-trans）, we found that the introduction of the N atoms in the C-4 position could dramatically improve the water solubility（7b）, whereas protonation of the piperidine N atom resulted in a decrease in its hydrophobic interaction with the binding pocket. In particular, protonation altered the orientation of the alicyclic rings in the hydrophobic pocket, thus impeding the formation of key halogen bond and eventually leading to a huge change in anti-HIV-1 RT activity. These results provided theoretical and experimental basis for the subsequent structural modification of pyridinone compounds.展开更多
BACKGROUND Gastrointestinal stromal tumors(GISTs) associated with neurofibromatosis are uncommon compared to their gastrointestinal counterparts. Patients with neurofibromatosis type 1(NF-1) have an increased risk of ...BACKGROUND Gastrointestinal stromal tumors(GISTs) associated with neurofibromatosis are uncommon compared to their gastrointestinal counterparts. Patients with neurofibromatosis type 1(NF-1) have an increased risk of developing gastrointestinal tumors, including rare types such as GIST.CASE SUMMARY A 60-year-old male Chinese patient was diagnosed with NF-1 10 years ago and presented with upper abdominal discomfort and black stools. Endoscopic ultrasonography and an enhanced abdominal computed tomography scan revealed a mass located 4 cm from the muscular layer of the descending duodenum. A 59-year-old Chinese woman who was diagnosed with NF-1 25 years ago presented with sudden unconsciousness and black stools. Multiple masses in the duodenum were noted by echogastroscopy and an enhanced abdominal computed tomography scan. Both patients presented with cutaneous neurofibromas. The histologic examination of tumors from both patients revealed spindle cells and low mitotic activity. Immunohistochemically, the tumor cells showed strong positivity for KIT(CD117), DOG-1, CD34, and Dehydrogenase Complex Subunit B, and negativity for SMA, desmin, S-100, and β-catenin. None of the six tumors from two patients had KIT exon 9, 11, 13, or 17 or platelet-derived growth factor receptor α exon 12 or 18 mutation, which is a typical finding for sporadic GISTs. None of the six tumors from the two patients had a BRAFV600 E mutation. The patients were alive and well during the follow-up period(range:0.6-5 yr).CONCLUSION There have been only a few previous reports of GISTs associated with NF-1.Although GISTs associated with NF-1 have morphologic and immunohistochemical similarities with GISTs, the pathogenesis, incidence,genetic background, and prognosis are not completely known. A medical history of NF-1 in a patient who has gastrointestinal bleeding or anemia and an intraabdominal mass with nonspecific computed tomography features may help in diagnosing GIST by virtue of the well-known association of these two entities.Molecular genetic studies of cases indicated that GISTs in NF-1 patients have a different pathogenesis than sporadic GISTs.展开更多
A series of novel 3-substituted-4-hydroxycoumarin derivatives 6（a-1） were synthesized in high yield using one-pot three component coupling reaction catalyzed by ceric ammonium nitrate. These compounds were evaluated...A series of novel 3-substituted-4-hydroxycoumarin derivatives 6（a-1） were synthesized in high yield using one-pot three component coupling reaction catalyzed by ceric ammonium nitrate. These compounds were evaluated for antileishmanial activity against Leishmania donovani promastigotes and antioxidant activity（DPPH-radical scavenging activity）. Two compounds, 6h（IC50= 9.90 μmol/L） and 6i（IC50= 6.90 μmol/L） displayed potent antileishmanial activity when compared with standard antileishmanial agents pentamidine（IC50= 16.15 μmol/L） and miltefosine（IC50= 12.50 μmol/L）. Three compounds, 6c（IC50= 10.79 μmol/L）, 6h（IC50= 10.60 μmol/L）, and 6i（IC50= 10.73 μmol/L） showed significant antioxidant activity favorably with the antioxidant standards butylated hydroxy toluene（IC50= 16.47 μmol/L） and ascorbic acid（IC50= 12.69 μmol/L）. A molecular docking study of compounds 6（a-1） suggested a possible mode of binding with the Adenine phosphoribosyltransferase enzyme of L.donovani. ADME properties were predicted in silico and support the potential of 6（a-1） to show favorable drug-like properties.展开更多
Introduction:</span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> Primary renal synovialosarcoma (SVS) is a rare and ag...Introduction:</span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> Primary renal synovialosarcoma (SVS) is a rare and aggressive disease in which the metastatic potential is very high. Its diagnosis is based on morphological and molecular studies. No therapeutic consensus has yet been established for this histological variant of renal cancer. We describe our experience with a patient followed at the Mohamed IV Center for cancer treatment for primary monophasic synovialosarcoma of the kidney. </span><span><span style="font-family:Verdana;">Case Presen</span><span style="font-family:Verdana;">tation: </span></span><span style="font-family:Verdana;">In October 2020, a 58-year-old patient with hypertension unde</span><span style="font-family:Verdana;">r treat</span><span style="font-family:Verdana;">ment, consulted for right back pain without hematuria or calculus emission. The initial examination found a slight right lumbar tenderness. Thoraco-abdominal computed tomography revealed a cystic lesion of the superior</span><span style="font-family:Verdana;"> pole of the right kidney without secondary lesions. Surgical treatment consisted of an enlarged </span><span style="font-family:Verdana;">right total nephrectomy using a bi-subcostal approach. The post-operative</span><span style="font-family:Verdana;"> consequences were simple. Histologically, it was a poorly differentiated cystic malignant tumor process measuring 17 cm long axis. The limits were healthy as well as the adrenal. Immunohistology made it possible to retain a monophasic synovialosarcoma. However</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">, </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">the patient did not receive genetic analysis. Given the poor prognosis of these tumors, treatment with adjuvant che</span><span style="font-family:Verdana;">motherapy and radiotherapy has been imposed;as indicated in our case.</span> <span style="font-family:Verdana;">Conclusion: </span><span style="font-family:Verdana;">Primary kidney SVS is a rare, aggressive disease with a poor prognosis. However, the prognosis may</span></span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">be improved by multimodal treatment. </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">A </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">positive diagnosis is difficult and can be confused with other types of renal carcinoma hence the interest </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">in</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> molecular biology.展开更多
基金HEC Pakistan, Department of Chemistry, COMSATS Abbottabad,for this project
文摘Bis-thiobarbiturate derivatives 1-15 have been synthesized, characterized by 1HNMR and El-MS and screened for urease inhibition. All compounds showed various degree of urease inhibitory activity with iC50 values ranging 7.45 ± 0.12 - 74.24 ± 0.81 μmol/L while the standard thiourea behaved normally （ICso = 21.10 ±0.12）. Compounds I （IC50= 7.45 ± 0.12 ]μmol/L）, 9 （IC50 =18,17 ± 1.03 bmol/L） and 13 （IC50= 8.61 ± 0.45 bmol/L） showed excellent urease inhibitory activity in the series. Molecular modeling studies were performed to understand the binding site with the bimetallic nickel center of the enzyme. Structure-activity relationship has also been established for these compounds. This study identified bis- thiobarbiturate as a novel class of urease inhibitors.
文摘A new series of benzothiazole Schiff bases 3–29 was synthesized and screened for antitumor activity against cervical cancer（Hela） and kidney fibroblast cancer（COS-7） cell lines. Results indicated that compounds 3, 14, 19, 27 and 28 have promising activity against Hela cell line with IC50 values of 2.41,3.06, 6.46, 2.22 and 6.25 mmol/L, respectively, in comparison to doxorubicin as a reference antitumor agent（IC50 2.05 mmol/L）. In addition, compound 3 displayed excellent activity against COS-7 cell line with IC50 value of 4.31 mmol/L in comparison to doxorubicin（IC50 3.04 mmol/L）. In the present work,structure based pharmacophore mapping, molecular docking, protein-ligand interaction, fingerprints and binding energy calculations were employed in a virtual screening strategy to identify the interaction between the compounds and the active site of the putative target, EGFR tyrosine kinase. Molecular properties, toxicity, drug-likeness, and drug score profiles of compounds 3, 14, 19, 27, 28 and 29 were also assessed.
文摘Adsorption-desorption kinetics of CO and H_2 on Ni surface were studied with molecular beam relaxation spectrometry. It is found that there are two adsorbed states in the substrate temperature range 330K<T<480K and 720K<T<900K respectively for CO/Ni system. These results can be explained by a precursor state model. Their kinetic parameters: E_(aα)=14.6kJ/mol, E_(dx)=49.3kJ/mol; E_(aβ)= 68.6kJ/mol, E_(dβ)=200.6kJ/mol. It is shown that there are two adsorbed states in the low (350K<T<430K) and high (550K<T<625K) temperature range respectively for H_2/Ni system. These results can be explained by a direct dissociative model. Their kinetic parameters:E_(dl)=26.3kJ/mol, E_(dh)=103.7kJ/mol.
基金Project supported by National Natural Science Foundation of China
文摘Here some steady-state experiments on oxidation of CO on Pd were performed on a molecular beam apparatus. It is found that the characteristics of the rate of CO_2 formation r versus substrate temperature T are dependent on the ratio P=P_(CO)/P_(O2) in the mixed beam. These characteristics are related to the complicated interactions of co-adsorbed CO and O particles on Pd surface.
文摘Molecular testing in thyroid nodules and thyroid cancer is rapidly evolving;care must be used when incorporating molecular testing for thyroid nodules into clinical practice. A clear appreciation of the goals and restraints of molecular testing must be integrated into how physicians use and explain molecular testing to patients. Molecular tests can help rule in cancer for indeterminate thyroid nodules with very specific mutations for thyroid cancer, such as BRAF and RET/PTC, and can help reduce the rates of completion thyroidectomies in this era of de-escalation of the management of thyroid disease. The positive predictive value (PPV) of malignant cytology (Bethesda VI) is 98%;and even though molecular testing improves specificity and PPV, it falls short of this ideal for other mutations. We present a detailed evaluation of the current state of molecular testing and their clinical relevance in the setting of diagnostic utility and their impact on surgical decision-making. By recapitulating the clinical impact of these tests and some of the related drawbacks, we hope to provide adequate up to date information of the appropriate utilization of these tools in the management of indeterminate or suspicious thyroid nodules and highlight future directions on their utilization for the management of thyroid cancer.
基金financially supported by the National Natural Science Foundation of China(No.51922026)the Fundamental Research Funds for the Central Universities(Nos.N2002005 and N2007011)+1 种基金the Liaoning Natural Science Foundation(No.20180510010)the 111 Project(No.B20029)。
文摘Mechanical properties of high-entropy alloys(HEAs)with the face-centered cubic(fcc)structure strongly depend on their initial grain orientations.However,the orientation-dependent mechanical responses and the underlying plastic fl ow mechanisms of such alloys are not yet well understood.Here,deformation of the equiatomic FeMnCoCrNi HEA with various initial orientations under uniaxial tensile testing has been studied by using atomistic simulations,showing the results consistent with the recent experiments on fcc HEAs.The quantitative analysis of the activated deformation modes shows that the initiation of stacking faults is the main plastic deformation mechanism for the crystals initially oriented with[001],[111],and[112],and the total dislocation densities in these crystals are higher than that with the[110]and[123]orientations.Stacking faults,twinning,and hcp-martensitic transformation jointly promote the plastic deformation of the[110]orientation,and twinning in this crystal is more significant than that with other orientations.Deformation in the crystal oriented with[123]is dominated by the hcp-martensite transformation.Comparison of the mechanical behaviors in the FeMnCoCrNi alloy and the conventional materials,i.e.Cu and Fe50Ni50,has shown that dislocation slip tends to be activated more readily in the HEA.This is attributed to the larger lattice distortion in the HEA than the low-entropy materials,leading to the lower critical stress for dislocation nucleation and elastic–plastic transition in the former.In addition,the FeMnCoCrNi HEA with the larger lattice distortion leads to an enhanced capacity of storing dislocations.However,for the[001]-oriented HEA in which dislocation slip and stacking fault are the dominant deformation mechanisms,the limited deformation modes activated are insu fficient to improve the work hardening ability of the material.
文摘Objective: To study the treatment of B-Thalas-semia (ThE) with Chinese herbal medicine for Bushen Yisui (BSYS), its theoretical base and molecular mechanism. Methods: Seventy-eight patients with ThE were treated with BSYS recipe (consisted of 11 Chinese herbal drugs as Dogwood fruit, Fleeceflower root, prepared Rehmannia root and turtle shell, etc.) orally taken, 3 times per day, 10 g/time, 3 months as one therapeutic course. Hemoglobin (Hb), red blood cell (RBC), reticulocyte (Ret) and hemoglobin F (HbF) were checked every month. At the same time, PAGE, PVR, PCR-SSCP, RT-PCR, DNA series analysis, mRNA gene expression analysis techniques were used to conduct the systematic gene analysis in patients to study the molecular mechanism of TCM treatment from aspects of gene mutation, gene expression and control-regulation. Results: All the blood criteria in patients after BSYS treatment were improved significantly with clinical symptoms
文摘Molecular dynamics simulations are carried out in order to Study the atomic structure of crystalline component of nanocrystalline α-Fe when it is consolidated from small grains. A two-dimensional computational block is used to simulate the consolidation process. All the preset dislocations in the original grains glide out of them in the consolidation process, but new dislocations can generate when the grain size is large enough. It shows that dislocations exist in the consolidated material rather than in the original grains. Whether dislocations exist in the crystalline component of the resultant model nano-material depends upon grain size. The critical value of grain size for dislocation generation appears to be about 9 nm. This result agrees with experiments qualitatively.
文摘A computer program has been developed for the moIlcular dynamics calculation of ionic orstrong-ionic covalent systems. Ewald summation algorithm and Keating potentiaI model areadopted to calculate the long-range Coulomb interaction and the short-range bonding forces,respectively. A theoretical study on the domain boundary structures in epitaxial wurtzite GaN film is accomplished with the program. The calculation result is used in the structure formationexplanation of an interesting defect observed by HREM experiment.
文摘The localized molecular orbitals for typical bowl-shaped circulenes are obtained by the use of INDO-LMO method. It is found that these bowl-shaped circulenes with strained π-electron systems are still aromatic and the rim π-bonds with larger localization form reactive regions for formation of buckminsterfullerene.
基金Supported by the National Natural Science Foundation of China under Grant No 11274262the Natural Science Foundation of Hunan Province under Grand No 14JJ2046the Program for Changjiang Scholars and Innovative Research Team in Universities under Grant No IRT13093
文摘Molecular dynamics simulations are performed to study the nanoindentation models of monolayer suspended graphene and graphyne. Fullerenes are selected as indenters. Our results show that Young＇s modulus of monolayer-thick graphyne is almost half of that of graphene, which is estimated to be 0.50 TPa. The mechanical properties of graphene and graphyne are different in the presence of strain. A pre-tension has an important effect on the mechanical properties of a membrane. Both the pre-tension and Young＇s modulus plots demonstrate index behavior. The toughness of graphyne is stronger than that of graphene due to Young＇s modulus magnitude. Young＇s moduli of graphene and graphyne are almost independent of the size ratio of indenter to membrane.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11374336 and 61176078
文摘We perform molecular beam epitaxy growth and scanning tunneling microscopy study of copper diselenide （CuSe2 ） films on SrTiO3 （001）. Using a Se-rich condition, the single-phase pyrite CuSe2 grows in the Stranski-Krastanov （layer-plus-island） mode with a preferential orientation of （111）. Our careful inspection of both the as-grown and post-annealed CuSe2 films at various temperatures invariably shows a Cu-terminated surface, which, depending on the annealing temperature, reconstructs into two distinct structures 2 ×√3 and √x ×√3-R30°. The Cu termi- nation is supported by the depressed density of states near the Fermi level, measured by in-situ low temperature scanning tunneling spectroscopy. Our study helps understand the preparation and surface chemistry of transition metal pyrite dichalcogenides thin films.
文摘Photoinhibition occurs when crops grow under strong light and are simultaneously subjected to stresses such as high or low temperature, drought,etc. It causes a decrease of crop photosynthetic efficiency leading to an obvious decrease of the yield.
文摘The term thyroid neoplasm incorporates tumors that originate from follicular cells and those that arise from parafollicular cells (C cells). Differentiated thyroid cancer, which originates from follicular cells, includes papillary thyroid carcinoma (PTC), follicular thyroid carcinoma (FTC), oncocytic cell carcinoma (Hürthle), poorly differentiated carcinoma, and anaplastic thyroid carcinoma (ATC). PTC tends to have an indolent clinical course with low morbidity and mortality. However, this entity has a broad range of biological and clinical behavior that can result in disease recurrence and death, depending on patient and tumor characteristics and the initial treatment approach. PTC is the most common form of well-differentiated thyroid cancer (WDTC) and based on the most recent statistics, accounts for approximately 89.4% of all thyroid malignancies. PTC appears as an irregular solid or cystic nodule in normal thyroid parenchyma. PTC has the propensity for lymphatic invasion, but it is less likely to have hematogenous spread. Around 11% of patients with PTC present with distant metastases outside the neck and mediastinum. This manuscript with review the current understanding of the epidemiology, pathology, molecular characteristics, prognostic factors, and dynamic risk stratification of PTC centered on an evidence-based and personalized approach.
基金This work was supported by grants from the National Natural Science Foundation of China(Grant No.:82072142)the National Key R&D Program of China(Grant No.:2020YFC2005502)the Science and Technology Commission of Shanghai Municipality(Grant No.:19401900500).
文摘The surface plasmon resonance(SPR)biosensor technology is a novel optical analysis method for studying intermolecular interactions.Owing to in-depth research on traditional Chinese medicine(TCM)in recent years,comprehensive and specific identification of components and target interactions has become key yet difficult tasks.SPR has gradually been used to analyze the active components of TCM owing to its high sensitivity,strong exclusivity,large flux,and real-time monitoring capabilities.This review sought to briefly introduce the active components of TCM and the principle of SPR,and provide historical and new insights into the application of SPR in the analysis of the active components of TCM.
基金The National Natural Science Foundation of China(Grant No.21172014,20972011 and 21042009)
文摘Among the structurally diverse NNRTIs, pyridinone scaffolds demonstrate high potency against HIV-1 wild type and drug-resistant strains. During the optimization of our pyridinone compound 1（LAM-trans）, we found that the introduction of the N atoms in the C-4 position could dramatically improve the water solubility（7b）, whereas protonation of the piperidine N atom resulted in a decrease in its hydrophobic interaction with the binding pocket. In particular, protonation altered the orientation of the alicyclic rings in the hydrophobic pocket, thus impeding the formation of key halogen bond and eventually leading to a huge change in anti-HIV-1 RT activity. These results provided theoretical and experimental basis for the subsequent structural modification of pyridinone compounds.
基金Supported by National Natural Science Foundation of China,No.81601692Program of Liaoning Province Department of Education,No.LK2016002
文摘BACKGROUND Gastrointestinal stromal tumors(GISTs) associated with neurofibromatosis are uncommon compared to their gastrointestinal counterparts. Patients with neurofibromatosis type 1(NF-1) have an increased risk of developing gastrointestinal tumors, including rare types such as GIST.CASE SUMMARY A 60-year-old male Chinese patient was diagnosed with NF-1 10 years ago and presented with upper abdominal discomfort and black stools. Endoscopic ultrasonography and an enhanced abdominal computed tomography scan revealed a mass located 4 cm from the muscular layer of the descending duodenum. A 59-year-old Chinese woman who was diagnosed with NF-1 25 years ago presented with sudden unconsciousness and black stools. Multiple masses in the duodenum were noted by echogastroscopy and an enhanced abdominal computed tomography scan. Both patients presented with cutaneous neurofibromas. The histologic examination of tumors from both patients revealed spindle cells and low mitotic activity. Immunohistochemically, the tumor cells showed strong positivity for KIT(CD117), DOG-1, CD34, and Dehydrogenase Complex Subunit B, and negativity for SMA, desmin, S-100, and β-catenin. None of the six tumors from two patients had KIT exon 9, 11, 13, or 17 or platelet-derived growth factor receptor α exon 12 or 18 mutation, which is a typical finding for sporadic GISTs. None of the six tumors from the two patients had a BRAFV600 E mutation. The patients were alive and well during the follow-up period(range:0.6-5 yr).CONCLUSION There have been only a few previous reports of GISTs associated with NF-1.Although GISTs associated with NF-1 have morphologic and immunohistochemical similarities with GISTs, the pathogenesis, incidence,genetic background, and prognosis are not completely known. A medical history of NF-1 in a patient who has gastrointestinal bleeding or anemia and an intraabdominal mass with nonspecific computed tomography features may help in diagnosing GIST by virtue of the well-known association of these two entities.Molecular genetic studies of cases indicated that GISTs in NF-1 patients have a different pathogenesis than sporadic GISTs.
文摘A series of novel 3-substituted-4-hydroxycoumarin derivatives 6（a-1） were synthesized in high yield using one-pot three component coupling reaction catalyzed by ceric ammonium nitrate. These compounds were evaluated for antileishmanial activity against Leishmania donovani promastigotes and antioxidant activity（DPPH-radical scavenging activity）. Two compounds, 6h（IC50= 9.90 μmol/L） and 6i（IC50= 6.90 μmol/L） displayed potent antileishmanial activity when compared with standard antileishmanial agents pentamidine（IC50= 16.15 μmol/L） and miltefosine（IC50= 12.50 μmol/L）. Three compounds, 6c（IC50= 10.79 μmol/L）, 6h（IC50= 10.60 μmol/L）, and 6i（IC50= 10.73 μmol/L） showed significant antioxidant activity favorably with the antioxidant standards butylated hydroxy toluene（IC50= 16.47 μmol/L） and ascorbic acid（IC50= 12.69 μmol/L）. A molecular docking study of compounds 6（a-1） suggested a possible mode of binding with the Adenine phosphoribosyltransferase enzyme of L.donovani. ADME properties were predicted in silico and support the potential of 6（a-1） to show favorable drug-like properties.
文摘Introduction:</span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> Primary renal synovialosarcoma (SVS) is a rare and aggressive disease in which the metastatic potential is very high. Its diagnosis is based on morphological and molecular studies. No therapeutic consensus has yet been established for this histological variant of renal cancer. We describe our experience with a patient followed at the Mohamed IV Center for cancer treatment for primary monophasic synovialosarcoma of the kidney. </span><span><span style="font-family:Verdana;">Case Presen</span><span style="font-family:Verdana;">tation: </span></span><span style="font-family:Verdana;">In October 2020, a 58-year-old patient with hypertension unde</span><span style="font-family:Verdana;">r treat</span><span style="font-family:Verdana;">ment, consulted for right back pain without hematuria or calculus emission. The initial examination found a slight right lumbar tenderness. Thoraco-abdominal computed tomography revealed a cystic lesion of the superior</span><span style="font-family:Verdana;"> pole of the right kidney without secondary lesions. Surgical treatment consisted of an enlarged </span><span style="font-family:Verdana;">right total nephrectomy using a bi-subcostal approach. The post-operative</span><span style="font-family:Verdana;"> consequences were simple. Histologically, it was a poorly differentiated cystic malignant tumor process measuring 17 cm long axis. The limits were healthy as well as the adrenal. Immunohistology made it possible to retain a monophasic synovialosarcoma. However</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">, </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">the patient did not receive genetic analysis. Given the poor prognosis of these tumors, treatment with adjuvant che</span><span style="font-family:Verdana;">motherapy and radiotherapy has been imposed;as indicated in our case.</span> <span style="font-family:Verdana;">Conclusion: </span><span style="font-family:Verdana;">Primary kidney SVS is a rare, aggressive disease with a poor prognosis. However, the prognosis may</span></span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">be improved by multimodal treatment. </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">A </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">positive diagnosis is difficult and can be confused with other types of renal carcinoma hence the interest </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">in</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> molecular biology.
