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1.
Zhonghua Xue Ye Xue Za Zhi ; 45(1): 41-47, 2024 Jan 14.
Article in Chinese | MEDLINE | ID: mdl-38527837

ABSTRACT

Objective: To evaluate the efficacy and prognostic factors of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with secondary acute myeloid leukemia (sAML) . Methods: In this multicenter, retrospective clinical study, adult patients aged ≥18 years who underwent allo-HSCT for sAML at four centers of the Zhejiang Hematopoietic Stem Cell Transplantation Collaborative Group from January 2014 to November 2022 were included, and the efficacy and prognostic factors of allo-HSCT were analyzed. Results: A total of 95 patients were enrolled; 66 (69.5%) had myelodysplastic syndrome-acute myeloid leukemia (MDS-AML) , 4 (4.2%) had MDS/MPN-AML, and 25 (26.3%) had therapy-related AML (tAML) . The 3-year CIR, LFS, and overall survival (OS) rates were 18.6% (95% CI 10.2%-27.0%) , 70.6% (95% CI 60.8%-80.4%) , and 73.3% (95% CI 63.9%-82.7%) , respectively. The 3-year CIRs of the M-AML group (including MDS-AML and MDS/MPN-AML) and the tAML group were 20.0% and 16.4%, respectively (P=0.430) . The 3-year LFSs were 68.3% and 75.4%, respectively (P=0.176) . The 3-year OS rates were 69.7% and 75.4%, respectively (P=0.233) . The 3-year CIRs of the groups with and without TP53 mutations were 60.0% and 13.7%, respectively (P=0.003) ; the 3-year LFSs were 20.0% and 76.5%, respectively (P=0.002) ; and the 3-year OS rates were 40.0% and 77.6%, respectively (P=0.002) . According to European LeukmiaNet 2022 (ELN2022) risk stratification, the 3-year CIRs of patients in the low-, intermediate-, and high-risk groups were 8.3%, 17.8%, and 22.6%, respectively (P=0.639) . The three-year LFSs were 91.7%, 69.5%, and 65.6%, respectively (P=0.268) . The 3-year OS rates were 91.7%, 71.4%, and 70.1%, respectively (P=0.314) . Multivariate analysis revealed that advanced disease at allo-HSCT and TP53 mutations were independent risk factors for CIR, LFS, and OS. Conclusion: There was no significant difference in the prognosis of patients who underwent allo-HSCT among the MDS-AML, MDS/MPN-AML, and tAML groups. Advanced disease at transplantation and TP53 mutations were poor prognostic factors. ELN2022 risk stratification had limited value for predicting the prognosis of patients with sAML following allo-HSCT.


Subject(s)
Hematopoietic Stem Cell Transplantation , Leukemia, Myeloid, Acute , Myelodysplastic Syndromes , Neoplasms, Second Primary , Adult , Humans , Adolescent , Prognosis , Retrospective Studies , Myelodysplastic Syndromes/therapy , Leukemia, Myeloid, Acute/therapy , Leukemia, Myeloid, Acute/genetics , Hematopoietic Stem Cell Transplantation/adverse effects , Neoplasms, Second Primary/etiology
2.
Phys Rev Lett ; 130(21): 216004, 2023 May 26.
Article in English | MEDLINE | ID: mdl-37295091

ABSTRACT

There has been a long-standing debate about the mechanism of the unusual superconductivity in alkali-intercalated fullerides. In this Letter, using high-resolution angle-resolved photoemission spectroscopy, we systematically investigate the electronic structures of superconducting K_{3}C_{60} thin films. We observe a dispersive energy band crossing the Fermi level with the occupied bandwidth of about 130 meV. The measured band structure shows prominent quasiparticle kinks and a replica band involving the Jahn-Teller active phonon modes, which reflects strong electron-phonon coupling in the system. The electron-phonon coupling constant is estimated to be about 1.2, which dominates the quasiparticle mass renormalization. Moreover, we observe an isotropic nodeless superconducting gap beyond the mean-field estimation (2Δ/k_{B}T_{c}≈5). Both the large electron-phonon coupling constant and large reduced superconducting gap suggest a strong-coupling superconductivity in K_{3}C_{60}, while the electronic correlation effect is suggested by the observation of a waterfall-like band dispersion and the small bandwidth compared with the effective Coulomb interaction. Our results not only directly visualize the crucial band structure but also provide important insights into the mechanism of the unusual superconductivity of fulleride compounds.


Subject(s)
Alkalies , Electrons , Photoelectron Spectroscopy
3.
Rev Sci Instrum ; 94(2): 023903, 2023 Feb 01.
Article in English | MEDLINE | ID: mdl-36859063

ABSTRACT

Angle-resolved photoemission spectroscopy with sub-micrometer spatial resolution (µ-ARPES), has become a powerful tool for studying quantum materials. To achieve sub-micrometer or even nanometer-scale spatial resolution, it is important to focus the incident light beam (usually from synchrotron radiation) using x-ray optics, such as the zone plate or ellipsoidal capillary mirrors. Recently, we developed a laser-based µ-ARPES with spin-resolution (LMS-ARPES). The 177 nm laser beam is achieved by frequency-doubling a 355 nm beam using a KBBF crystal and subsequently focused using an optical lens with a focal length of about 16 mm. By characterizing the focused spot size using different methods and performing spatial-scanning photoemission measurement, we confirm the sub-micron spatial resolution of the system. Compared with the µ-ARPES facilities based on the synchrotron radiation, our LMS-ARPES system is not only more economical and convenient, but also with higher photon flux (>5 × 1013 photons/s), thus enabling the high-resolution and high-statistics measurements. Moreover, the system is equipped with a two-dimensional spin detector based on exchange scattering at a surface-passivated iron film grown on a W(100) substrate. We investigate the spin structure of the prototype topological insulator Bi2Se3 and reveal a high spin-polarization rate, confirming its spin-momentum locking property. This lab-based LMS-ARPES will be a powerful research tool for studying the local fine electronic structures of different condensed matter systems, including topological quantum materials, mesoscopic materials and structures, and phase-separated materials.

4.
Phys Rev Lett ; 129(15): 156401, 2022 Oct 07.
Article in English | MEDLINE | ID: mdl-36269973

ABSTRACT

Chiral materials have attracted significant research interests as they exhibit intriguing physical properties, such as chiral optical response, spin-momentum locking, and chiral induced spin selectivity. Recently, layered transition metal dichalcogenide 1T-TaS_{2} has been found to host a chiral charge density wave (CDW) order. Nevertheless, the physical consequences of the chiral order, for example, in electronic structures and the optical properties, are yet to be explored. Here, we report the spectroscopic visualization of an emergent chiral electronic band structure in the CDW phase, characterized by windmill-shaped Fermi surfaces. We uncover a remarkable chirality-dependent circularly polarized Raman response due to the salient in-plane chiral symmetry of CDW, although the ordinary circular dichroism vanishes. Chiral Fermi surfaces and anomalous Raman responses coincide with the CDW transition, proving their lattice origin. Our Letter paves a path to manipulate the chiral electronic and optical properties in two-dimensional materials and explore applications in polarization optics and spintronics.

5.
Nat Commun ; 13(1): 726, 2022 Feb 07.
Article in English | MEDLINE | ID: mdl-35132071

ABSTRACT

Nanometer-thick passive films, which impart superior corrosion resistance to metals, are degraded in long-term service; they are also susceptible to chloride-induced localized attack. Here we show, by engineering crystallographic configurations upon metal matrices adjacent to their passive films, we obtain great enhancement of corrosion resistance of FeCr15Ni15 single crystal in sulphuric acid, with activation time up to two orders of magnitude longer than that of the non-engineered counterparts. Meanwhile, engineering crystallography decreases the passive current density and shifts the pitting potential to noble values. Applying anodic polarizations under a transpassivation potential, we make the metal matrices underneath the transpassive films highly uneven with {111}-terminated configurations, which is responsible for the enhancement of corrosion resistance. The transpassivation strategy also works in the commercial stainless steels where both grain interior and grain boundaries are rebuilt into the low-energy configurations. Our results demonstrate a technological implication in the pretreatment process of anti-corrosion engineering.

6.
Nat Commun ; 12(1): 6183, 2021 Oct 26.
Article in English | MEDLINE | ID: mdl-34702828

ABSTRACT

(Quasi-)one-dimensional systems exhibit various fascinating properties such as Luttinger liquid behavior, Peierls transition, novel topological phases, and the accommodation of unique quasiparticles (e.g., spinon, holon, and soliton, etc.). Here we study molybdenum blue bronze A0.3MoO3 (A = K, Rb), a canonical quasi-one-dimensional charge-density-wave material, using laser-based angle-resolved photoemission spectroscopy. Our experiment suggests that the normal phase of A0.3MoO3 is a prototypical Luttinger liquid, from which the charge-density-wave emerges with decreasing temperature. Prominently, we observe strong renormalizations of band dispersions, which are recognized as the spectral function of Holstein polaron derived from band-selective electron-phonon coupling in the system. We argue that the strong electron-phonon coupling plays an important role in electronic properties and the charge-density-wave transition in blue bronzes. Our results not only reconcile the long-standing heavy debates on the electronic properties of blue bronzes but also provide a rare platform to study interesting excitations in Luttinger liquid materials.

7.
Zhonghua Wei Chang Wai Ke Za Zhi ; 24(9): 830-835, 2021 Sep 25.
Article in Chinese | MEDLINE | ID: mdl-34530567

ABSTRACT

Intra-abdominal desmoid tumor (IADT) and gastrointestinal stromal tumor (GIST) are both mesenchymal tumors mostly found in gastrointestinal tracts and easily misdiagnosed, which would directly damage the survival prognosis and quality of life of patients. With the advent of the era of precision medicine, the understanding of the above two diseases is more in-depth, and the requirements for accurate diagnosis and individualized precision treatment are more stringent. Moreover, there seems to be some internal relationship between IADT and GIST, and the lack of systematic research and discussion makes clinical decision-making and patient management easy to fall into traps and misunderstandings. Therefore, this paper reviews the clinical characteristics, pathogenesis and treatments of the two, and explore their differences and internal relations, so as to provide research and practical reference for promoting more precise and individualized diagnosis and treatment regimens.


Subject(s)
Fibromatosis, Aggressive , Gastrointestinal Stromal Tumors , Clinical Decision-Making , Fibromatosis, Aggressive/diagnosis , Gastrointestinal Stromal Tumors/diagnosis , Humans , Prognosis , Quality of Life
8.
Zhonghua Wei Chang Wai Ke Za Zhi ; 24(9): 804-813, 2021 Sep 25.
Article in Chinese | MEDLINE | ID: mdl-34530562

ABSTRACT

Objective: To investigate the clinicopathological features of gastrointestinal stromal tumor (GIST) with KIT/PDGFRA "homozygous mutation", the efficacy of targeted therapy and the prognosis. Methods: A retrospective cohort study and propensity score matching were used. "Homozygous mutation" was defined as the detection of KIT/PDGFRA gene status of GIST by Sanger sequencing, which showed that there was only mutant gene sequence in the sequencing map, lack of wild-type sequence or the peak height of mutant gene sequence was much higher than that of wild-type gene sequence (> 3 times). "Heterozygous mutation" was defined as the mutant gene sequences coexisted with wild type gene sequences, and the peak height was similar (3 times or less). The clinicopathological data and follow-up information of 92 GIST patients with KIT/PDGFRA "homozygous mutation" were collected from 4 hospitals in Shanghai from January 2008 to May 2021 (Renji Hospital, Shanghai Jiaotong University School of Medicine: 70 cases; Zhongshan Hospital, Fudan University: 14 cases; Changhai Hospital, Naval Military Medical University: 6 cases and Ruijin Hospital, Shanghai Jiaotong University School of Medicine: 2 cases). Patients with perioperative death, other malignancies, and incomplete clinicopathological information were excluded. The clinicopathological features of the patients and the efficacy of targeted drug therapy were observed and analyzed. The efficacy was evaluated using Choi criteria, which were divided into complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD). In addition, a total of 230 patients with high-risk GIST with "heterozygous mutation" in exon 11 of KIT gene and 117 patients with recurrent or metastatic GIST with "heterozygous mutation" in exon 11 of KIT gene were included. The propensity score matching method was used to match GIST patients with "heterozygous" and "homozygous" mutations in exon 11 of KIT gene (1∶1) for survival analysis. The disease-free survival (DFS) between two groups of high-risk GIST patients who underwent complete surgical resection were compared. And progression-free survival (PFS) in patients with recurrent or metastatic GIST were compared. Results: Of the 92 GIST cases with KIT/PDGFRA "homozygous mutation", 58 were males and 34 were females, with a median onset age of 62 (31-91) years. Primary GIST 83 cases. Primary high-risk GIST (53 cases), metastatic GIST (21 cases) and recurrent GIST (9 cases) accounted for 90.2% (83/92). There were 90 cases of KIT gene"homozygous mutation" (exon 11 for 88 cases, exon 13 for 1 case, exon 17 for 1 case), and 2 cases of PDGFRA gene "homozygous mutation" (exon 12 for 1 case, exon 18 for 1 case). The median follow-up time was 49 (8-181) months. Among the 61 cases of primary localized GIST undergoing complete surgical resection, 2 cases were intermediate-risk GIST, 5 cases were low-risk GIST, and 1 case was very low-risk GIST, of whom 1 case of intermediate-risk GIST received 1-year adjuvant imatinib mesylate (IM) therapy after operation, and no tumor recurrence developed during the follow-up period. The remaining 53 cases were high-risk GIST, and follow-up data were obtained from 50 cases, of whom 22 developed tumor recurrence during follow-up. Of 9 patients directly receiving neoadjuvant targeted therapy (IM or avapritinib), 5 had complete imaging follow-up data, and the evaluation of efficacy achieved PR. Of all the 92 GIST cases with KIT/PDGFRA "homozygous mutation", 50 (54.4%) had tumor metastasis or tumor recurrence or progression during follow-up, and 12 (13.0%) died of the tumor. Survival analysis combined with propensity score showed that in 100 cases of high-risk GISTs with complete resection, GISTs with "homozygous mutation" in exon 11 of KIT gene had shorter disease-free survival (DFS) than GISTs with "heterozygous mutation" in exon 11 of KIT gene (median DFS: 72 months vs. 148 months, P=0.015). In 60 cases of recurrent or metastatic GISTs with KIT gene exon 11 mutation, IM was used as the first-line treatment, and the progression-free survival (PFS) of GISTs with "homozygous mutation" was shorter compared to GISTs with "heterozygous mutation" (median PFS: 38 months vs. 69 months, P=0.044). The differences were statistically significant. Conclusions: "Homozygous mutation" in KIT/PDGFRA gene is associated with the progression of GIST. The corresponding targeted therapeutic drugs are still effective for GIST with KIT/PDGFRA gene "homozygous mutation". Compared with GIST patients with "heterozygous mutation" in KIT exon 11, GIST patients with "homozygous mutation" in KIT exon 11 are more likely to relapse after surgery and to develop resistance to IM. Therefore, it is still necessary to seek more effective treatment methods for this subset of cases.


Subject(s)
Antineoplastic Agents , Gastrointestinal Stromal Tumors , Aged , Aged, 80 and over , Antineoplastic Agents/therapeutic use , China , Female , Gastrointestinal Stromal Tumors/drug therapy , Gastrointestinal Stromal Tumors/genetics , Humans , Male , Middle Aged , Mutation , Neoplasm Recurrence, Local , Prognosis , Proto-Oncogene Proteins c-kit/genetics , Pyrazoles , Pyrroles , Receptor, Platelet-Derived Growth Factor alpha/genetics , Retrospective Studies , Triazines
9.
Zhonghua Wei Chang Wai Ke Za Zhi ; 24(9): 796-803, 2021 Sep 25.
Article in Chinese | MEDLINE | ID: mdl-34530561

ABSTRACT

Objective: Contrast-enhanced CT is an important method of preoperative diagnosis and evaluation for the malignant potential of gastric submucosal tumor (SMT). It has a high diagnostic accuracy rate in differentiating gastric gastrointestinal stromal tumor (GIST) with a diameter greater than 5 cm from gastric benign SMT. This study aimed to use deep learning algorithms to establish a diagnosis model (GISTNet) based on contrast-enhanced CT and evaluate its diagnostic value in distinguishing gastric GIST with a diameter ≤ 5 cm and other gastric SMT before surgery. Methods: A diagnostic test study was carried out. Clinicopathological data of 181 patients undergoing resection with postoperative pathological diagnosis of gastric SMT with a diameter ≤ 5 cm at Department of Gastrointestinal Surgery of Renji Hospital from September 2016 to April 2021 were retrospectively collected. After excluding 13 patients without preoperative CT or with poor CT imaging quality, a total of 168 patients were enrolled in this study, of whom, 107 were GIST while 61 were benign SMT (non-GIST), including 27 leiomyomas, 24 schwannomas, 6 heterotopic pancreas and 4 lipomas. Inclusion criteria were as follows: (1) gastric SMT was diagnosed by contrast-enhanced CT before surgery; (2) preoperative gastroscopic examination and biopsy showed no abnormal cells; (3) complete clinical and pathological data. Exclusion criteria were as follows: (1) patients received anti-tumor therapy before surgery; (2) without preoperative CT or with poor CT imaging quality due to any reason; (3) except GIST, other gastric malignant tumors were pathologically diagnosed after surgery. Based on the hold-out method, 148 patients were randomly selected as the training set and 20 patients as the test set of the GISTNet diagnosis model. After the GISTNet model was established, 5 indicators were used for evaluation in the test set, including sensitivity, specificity, positive predictive value, negative predictive value and the area under the receiver operating curve (AUC). Then GISTNet diagnosis model was compared with the GIST-risk scoring model based on traditional CT features. Besides, in order to compare the accuracy of the GISTNet diagnosis model and the imaging doctors in the diagnosis of gastric SMT imaging, 3 radiologists with 3, 9 and 19 years of work experience, respectively, blinded to clinical and pathological information, tested and judged the samples. The accuracy rate between the three doctors and the GISTNet model was compared. Results: The GISTNet model yielded an AUC of 0.900 (95% CI: 0.827-0.973) in the test set. When the threshold value was 0.345, the sensitivity specificity, positive and negative predictive values of the GISTNet diagnosis model was 100%, 67%, 75% and 100%, respectively. The accuracy rate of the GISTNet diagnosis model was better than that of the GIST-risk model and the manual readings from two radiologists with 3 years and 9 years of work experience (83% vs. 75%, 60%, 65%), and was close to the manual reading of the radiologist with 19 years of work experience (83% vs. 80%). Conclusion: The deep learning algorithm based on contrast-enhanced CT has favorable and reliable diagnostic accuracy in distinguishing gastric GIST with a diameter ≤ 5 cm and other gastric SMT before operation.


Subject(s)
Deep Learning , Gastrointestinal Stromal Tumors , Stomach Neoplasms , Diagnosis, Differential , Gastrointestinal Stromal Tumors/diagnostic imaging , Humans , Retrospective Studies , Stomach Neoplasms/diagnostic imaging , Tomography, X-Ray Computed
10.
Nat Commun ; 12(1): 2874, 2021 May 17.
Article in English | MEDLINE | ID: mdl-34001892

ABSTRACT

Topological superconductors (TSCs) are unconventional superconductors with bulk superconducting gap and in-gap Majorana states on the boundary that may be used as topological qubits for quantum computation. Despite their importance in both fundamental research and applications, natural TSCs are very rare. Here, combining state of the art synchrotron and laser-based angle-resolved photoemission spectroscopy, we investigated a stoichiometric transition metal dichalcogenide (TMD), 2M-WS2 with a superconducting transition temperature of 8.8 K (the highest among all TMDs in the natural form up to date) and observed distinctive topological surface states (TSSs). Furthermore, in the superconducting state, we found that the TSSs acquired a nodeless superconducting gap with similar magnitude as that of the bulk states. These discoveries not only evidence 2M-WS2 as an intrinsic TSC without the need of sensitive composition tuning or sophisticated heterostructures fabrication, but also provide an ideal platform for device applications thanks to its van der Waals layered structure.

12.
Zhonghua Wei Chang Wai Ke Za Zhi ; 23(9): 872-879, 2020 Sep 25.
Article in Chinese | MEDLINE | ID: mdl-32927512

ABSTRACT

Objective: Platelet-derived growth factor alpha (PDGFRA) mutations are respectively rare in gastrointestinal stromal tumors (GIST). Most GIST with PDGFRA exon 18 mutations including D842V mutation are highly resistant to imatinib. The treatment of GIST harboring PDGFRA primary drug-resistant mutation is a major challenge. This article aims to investigate clinicopathologic features of GIST with PDGFRA-D842V mutation and the efficacy of comprehensive treatment, providing a reference for clinical practice. Methods: A retrospective cohort study was conducted to collect the clinicopathological and follow-up data of patients with GIST harboring PDGFRA mutation who were diagnosed and treated in the GIST Clinic of Renji Hospital from January 2005 to May 2020. According to the mutation site, the enrolled patients were divided into D842V mutation group and non-D842V mutation group. The differences of clinicopathologic characteristics between the two groups were compared. Furthermore, overall survival and prognostic factors were analyzed. Results: A total of 71 patients with PDGFRA-mutant GIST were included in this study, including 47 cases of D842V mutation (66.2%) and 24 cases of non-D842V mutation (33.8%). There were 28 male patients and 19 female patients in D842V mutation group, with a median age of 60 (36-82) years. There were 16 male patients and 8 female patients in non-D842V mutation group, with a median age of 62 (30-81) years. There were no significant differences in age, gender, primary location, surgical procedure, tumor size, mitotic count, expression of CD117 and DOG1, Ki-67 proliferation index and modified NIH grade between the two groups (all P>0.05). The positive rate of CD34 was 89.4% (42/47) and 62.5% (15/24) in the D842V mutation group and the non-D842V mutation group, respectively, with a statistically significant difference (χ(2)=5.644, P=0.018). Among all the cases, 66 cases underwent R0 resection without preoperative treatment; two cases underwent emergency operation with R1 resection because of tumor rupture; 2 cases were not operated after the pathological and mutation types were confirmed by biopsy (one case received avapritinib treatment and obtain partial remission). One case was diagnosed as wild-type GIST per needle biopsy in another institute, and underwent R0 resection after preoperative imatinib treatment for 6 months. After surgery, 5 high-risk GIST patients with D842V mutation and 5 high-risk GIST patients with non-D842V mutation were treated with imatinib for more than one year. The median follow-up time was 37 (1-153) months. As of the last follow-up among the patients who received R0 resection, 4 patients with D842V mutation had relapse, of whom 1 was in the period of imatinib administration, and the 3-year relapse-free survival rate was 94.2%; none of the patients with non-D842V mutation had relapse. There was no statistically significant difference in relapse-free surivval between two groups (P=0.233). Univariate analysis revealed that mitotic count (P=0.002), Ki-67 proliferation index (P<0.001) and modified NIH grade (P=0.025) were the factors associated with relapse-free survival of patients with D842V mutation after R0 resection (all P<0.05). However, the above factros were not testified as independant prognostic facors in multivariate Cox analysis (all P<0.05). Conclusion: Clinicopathologic features and the efficacy of radical resection in patients with PDGFRA-D842V mutation are similar to those in patients with non-D842V mutation.


Subject(s)
Gastrointestinal Neoplasms/diagnosis , Gastrointestinal Neoplasms/genetics , Gastrointestinal Stromal Tumors/diagnosis , Gastrointestinal Stromal Tumors/genetics , Receptor, Platelet-Derived Growth Factor alpha/genetics , Adult , Aged , Aged, 80 and over , Antineoplastic Agents/therapeutic use , Drug Resistance, Neoplasm/genetics , Exons , Female , Gastrointestinal Neoplasms/mortality , Gastrointestinal Neoplasms/therapy , Gastrointestinal Stromal Tumors/mortality , Gastrointestinal Stromal Tumors/therapy , Humans , Male , Middle Aged , Mutation , Prognosis , Retrospective Studies
13.
Nat Mater ; 19(8): 881-886, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32483242

ABSTRACT

A topological meron features a non-coplanar structure, whose order parameters in the core region are perpendicular to those near the perimeter. A meron is half of a skyrmion, and both have potential applications for information carrying and storage. Although merons and skyrmions in ferromagnetic materials can be readily obtained via inter-spin interactions, their behaviour and even existence in ferroelectric materials are still elusive. Here we observe using electron microscopy not only the atomic morphology of merons with a topological charge of 1/2, but also a periodic meron lattice in ultrathin PbTiO3 films under tensile epitaxial strain on a SmScO3 substrate. Phase-field simulations rationalize the formation of merons for which an epitaxial strain, as a single alterable parameter, plays a critical role in the coupling of lattice and charge. This study suggests that by engineering strain at the nanoscale it should be possible to fabricate topological polar textures, which in turn could facilitate the development of nanoscale ferroelectric devices.

14.
Climacteric ; 23(3): 279-287, 2020 06.
Article in English | MEDLINE | ID: mdl-32026732

ABSTRACT

Objective: The aim of the present study was to evaluate the effects of ethyl acetate extract of Polygonum orientale L. (POE) on ameliorating postmenopausal osteoporosis in ovariectomized (OVX) rats.Methods: Six-month-old female rats were randomly divided into seven groups: sham-operated; OVX; OVX with estradiol valerate; OVX with alendronate; and OVX with POE in graded doses (3.75, 5.0, or 7.5 g/kg/day). Administration began at week 6 after ovariectomy for 12 weeks. A comprehensive assessment of bone quality was performed, including serum biochemical markers, serum inflammatory factors, bone oxidative stress markers, bone mechanics, and bone histomorphometry.Results: POE treatment significantly decelerated OVX-induced body weight gain without affecting the uterus index and produced a significant decrease in the levels of serum bone turnover markers (p < 0.05 or p < 0.01). Biomechanical testing demonstrated that POE (5.0 and 7.5 g/kg/day) treatments significantly prevented the reduction in maximum stress and Young's modulus in OVX rats (p < 0.05). Compared with the OVX group, POE (3.75, 5.0, or 7.5 g/kg/day) treatments significantly increased trabecular bone mineral density by 35.03, 38.42, and 42.02%, respectively.Conclusion: Our findings suggest that POE has potential effects in regulation of bone metabolism and prevention of bone loss in postmenopausal osteoporosis.


Subject(s)
Osteoporosis, Postmenopausal/drug therapy , Plant Extracts/therapeutic use , Polygonum , Animals , Bone Density/drug effects , Bone Remodeling/drug effects , Disease Models, Animal , Female , Humans , Ovariectomy , Phytotherapy , Plant Extracts/pharmacology , Rats
15.
Phys Rev Lett ; 125(26): 266402, 2020 Dec 31.
Article in English | MEDLINE | ID: mdl-33449703

ABSTRACT

Impulsive optical excitation generally results in a complex nonequilibrium electron and lattice dynamics that involves multiple processes on distinct timescales, and a common conception is that for times shorter than about 100 fs the gap in the electronic spectrum is not seriously affected by lattice vibrations. Here, however, by directly monitoring the photoinduced collapse of the spectral gap in a canonical charge-density-wave material, the blue bronze Rb_{0.3}MoO_{3}, we find that ultrafast (∼60 fs) vibrational disordering due to efficient hot-electron energy dissipation quenches the gap significantly faster than the typical structural bottleneck time corresponding to one half-cycle oscillation (∼315 fs) of the coherent charge-density-wave amplitude mode. This result not only demonstrates the importance of incoherent lattice motion in the photoinduced quenching of electronic order, but also resolves the perennial debate about the nature of the spectral gap in a coupled electron-lattice system.

16.
Science ; 365(6459): 1282-1285, 2019 09 20.
Article in English | MEDLINE | ID: mdl-31604236

ABSTRACT

Weyl semimetals are crystalline solids that host emergent relativistic Weyl fermions and have characteristic surface Fermi-arcs in their electronic structure. Weyl semimetals with broken time reversal symmetry are difficult to identify unambiguously. In this work, using angle-resolved photoemission spectroscopy, we visualized the electronic structure of the ferromagnetic crystal Co3Sn2S2 and discovered its characteristic surface Fermi-arcs and linear bulk band dispersions across the Weyl points. These results establish Co3Sn2S2 as a magnetic Weyl semimetal that may serve as a platform for realizing phenomena such as chiral magnetic effects, unusually large anomalous Hall effect and quantum anomalous Hall effect.

17.
Zhonghua Wei Chang Wai Ke Za Zhi ; 22(9): 841-847, 2019 Sep 25.
Article in Chinese | MEDLINE | ID: mdl-31550823

ABSTRACT

Objective: To investigate the significance of monitoring imatinib mesylate (IM) plasma concentrations in patients with gastrointestinal stromal tumor (GIST). Methods: A retrospective descriptive study was carried out. Inclusion criteria: (1) patients with GIST confirmed by postoperative pathology or puncture pathology receiving maintenance therapy of IM; (2) administration of same dose of IM for at least 4 weeks (achieving steady - state plasma concentration). Patients who had severe organ dysfunction, received IM generics, or received IM simultaneously with other drugs significantly affecting IM pharmacokinetic were excluded. A total of 185 patients at the GIST Clinic of Renji Hospital, Shanghai Jiaotong University School of Medicine from August 2018 to May 2019 were enrolled, including 114 males (61.6%) and 71 females (38.4%) with a median age of 60 years old (range, 30-89 years), and 63 advanced cases. Patients receiving preoperative or postoperative adjuvant therapy were given IM 400 mg QD; patients with KIT exon 9 mutation or with disease progression during IM 400 mg QD treatment were given IM 600 mg QD. If the patient had adverse reactions such as myelosuppression during the medication, IM would be reduced or given BID per day. The peripheral venous blood was collected (22 to 24 hours after the last dose for patients who took IM QD and 2 hours before the first dose per day for those who took IM BID). IM plasma concentration was measured through high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). Correlation analysis between IM plasma concentration results and clinical data was performed using linear regression analysis. Results: A total of 241 stable blood samples of IM plasma concentration from 185 patients were finally collected. The IM plasma concentrations were significantly different between the doses of 300 mg/d and 400 mg/d [(942.4±433.5) µg/L vs. (1340.0±500.1) µg/L, t=6.317, P<0.001], and between 400 mg/d and 600 mg/d [(1340.0±500.1) µg/L vs. (2188.0±875.5) µg/L, t=3.557, P=0.004]. Among the blood samples of 57 patients receiving IM 300 mg/d, the IM plasma concentration of the advanced patients was significantly lower than that of the non-advanced patients [(795.6±225.8) µg/L vs. (992.2±484.4) µg/L, t=2.088, P=0.042]. Among the 137 blood samples of patients receiving IM 400 mg/d, the IM plasma concentration was higher in patients aged >60 years than those aged ≤60 years [(1461.0±595.3) µg/L vs. (1240.0±380.9) µg/L, t=2.528, P=0.013] and the IM plasma concentration of cases with diarrhea was significantly lower than that of those without diarrhea [(745.8±249.6) µg/L vs. (1382.0±486.9) µg/L, t=6.794, P<0.001]. Gender, primary location, surgical procedure, mutated gene, mutation type, or time of administration was associated with IM plasma concentration no matter in patients taking IM doses of 400 mg/d or 300 mg/d (all P>0.05). Regression analysis showed that body mass (P=0.004 and P=0.019), body mass index (P=0.016 and P=0.042), and body surface area (P=0.007 and P=0.028) were all negatively correlated with IM plasma concentrations in patients taking IM doses of 300 mg/d and 400 mg/d. Within the 137 patients who received a fixed oral dose of 400 mg/d IM, 17 patients received oral 200 mg BID, whose IM plasma drug concentration was not significantly different compared with that of 120 patients who received 400 mg IM QD [(1488.0±408.3) µg/L vs. (1319.0±509.7) µg/L, t=1.307, P=0.193]. Conclusions: Monitoring IM plasma concentration is significant throughout the whole process of management of GIST patients receiving IM treatment. In particular, regular monitoring IM plasma concentration and developing appropriate treatment strategies can bring better therapeutic benefits for patients with low doses, diarrhea, advanced condition and older age.


Subject(s)
Antineoplastic Agents , Gastrointestinal Stromal Tumors , Imatinib Mesylate , Adult , Aged , Aged, 80 and over , Antineoplastic Agents/blood , Antineoplastic Agents/therapeutic use , China , Female , Gastrointestinal Stromal Tumors/blood , Gastrointestinal Stromal Tumors/drug therapy , Humans , Imatinib Mesylate/blood , Imatinib Mesylate/therapeutic use , Male , Middle Aged , Retrospective Studies , Tandem Mass Spectrometry
19.
Nat Commun ; 10(1): 3478, 2019 Aug 02.
Article in English | MEDLINE | ID: mdl-31375677

ABSTRACT

Surface Fermi arcs (SFAs), the unique open Fermi-surfaces (FSs) discovered recently in topological Weyl semimetals (TWSs), are unlike closed FSs in conventional materials and can give rise to many exotic phenomena, such as anomalous SFA-mediated quantum oscillations, chiral magnetic effects, three-dimensional quantum Hall effect, non-local voltage generation and anomalous electromagnetic wave transmission. Here, by using in-situ surface decoration, we demonstrate successful manipulation of the shape, size and even the connections of SFAs in a model TWS, NbAs, and observe their evolution that leads to an unusual topological Lifshitz transition not caused by the change of the carrier concentration. The phase transition teleports the SFAs between different parts of the surface Brillouin zone. Despite the dramatic surface evolution, the existence of SFAs is robust and each SFA remains tied to a pair of Weyl points of opposite chirality, as dictated by the bulk topology.

20.
Zhonghua Xin Xue Guan Bing Za Zhi ; 47(7): 549-553, 2019 Jul 24.
Article in Chinese | MEDLINE | ID: mdl-31365996

ABSTRACT

Objective: To compare the efficacy and safety of active transfer of plaque (ATP) versus provisional stenting (PS) with drug-eluting stents (DES) for the treatment of coronary bifurcation lesions. Methods: A total of 1 136 patients with bifurcation lesions hospitalized in 6 selected hospitals between January 2010 and January 2014 were included in this prospective observational trial, patients were divided into either ATP (n=560) or PS group (n=576) accordingly. The primary endpoint was target lesion revascularization within 1 year, and the second endpoints were all-cause death, cardiogenic death, myocardial infarction, stent thrombosis, stroke, recurrent angina within 1 year. Results: There were no significant differences in age, sex, hypertension, diabetes, hyperlipidemia and smoking history between the two groups (P>0.05). The incidence of TIMI blood flow <3 grade in the side branch (1.6%(9/560) vs. 7.5% (43/576), P<0.01), acute occlusion of the side branch (1.3%(7/560) vs. 7.1%(41/576), P<0.01) and implanted stents of side branch (1.8%(10/560) vs. 7.8% (45/576), P<0.01) were significantly lower in the ATP group than those in the PS group. During the one year follow up, the rate of target lesion revascularization was similar between ATP group and PS group (4.6%(26/560) vs. 4.0%(23/576), P=0.66). Conclusions: The effectiveness and safetyof ATP techniquein the patients with coronary bifurcation lesions is comparable to the PS technique. However, ATP technique is superior to PS technique on effectively reducing the incidence of implanted stents in the side branch.


Subject(s)
Angioplasty, Balloon, Coronary , Coronary Artery Disease , Drug-Eluting Stents , Coronary Angiography , Humans , Prospective Studies , Stents , Time Factors , Treatment Outcome
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