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[Advances in clinical prediction scores for prognosis of coronavirus disease-2019]. ZHONGHUA JIE HE HE HU XI ZA ZHI = ZHONGHUA JIEHE HE HUXI ZAZHI = CHINESE JOURNAL OF TUBERCULOSIS AND RESPIRATORY DISEASES 2022; 45:706-711. [PMID: 35768378 DOI: 10.3760/cma.j.cn112147-20211125-00837] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Coronavirus Disease-2019 (COVID-19) has been a major public health issue all over the world, placing a significant burden on available healthcare resources. The most common types of COVID-19 are the mild and common forms. Although the proportion of the severe-critical types is smaller, the rate of death is significantly higher and the medical resources required tend to be greater. Thus, a variety of scores based on other disease and COVID-19 were used to assess the risk of poor prognosis on the COVID-19, including the common scores for community-acquired pneumonia, sepsis and viral pneumonia. Unfortunately, the above scores often lacked an adequate description of the applicable population or were at high risk of bias with unknown applicability. Therefore, the article summarized the existing scores, aiming to provide a reference for clinical prognostic risk assessment.
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[Clinical analysis of pulmonary nocardiosis associated with bronchiectasis]. ZHONGHUA JIE HE HE HU XI ZA ZHI = ZHONGHUA JIEHE HE HUXI ZAZHI = CHINESE JOURNAL OF TUBERCULOSIS AND RESPIRATORY DISEASES 2022; 45:276-281. [PMID: 35279991 DOI: 10.3760/cma.j.cn112147-20211128-00844] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Objective: To better understand the clinical characteristics of pulmonary nocardiosis associated with bronchiectasis. Methods: Patients diagnosed as bronchiectasis complicated with pulmonary nocardiosis in 9 tertiary general hospitals in China were enrolled from March 2016 to March 2020, with the record of general data, imaging performance and pathogen. The literature was reviewed. Results: Totally 17 patients were included. There were 12 females and 5 males. The ages ranged from 45 to 79 years, with an average of (63±9) years. There were 15 nonsmokers and 2 smokers, all of whom with chronic course. The clinical manifestations were mostly cough, expectoration, hemoptysis, fever, and dyspnea. The imaging manifestation was bronchiectasis in both lungs, with the most common involvement in the left lower lung, right middle lobe and left lingual lobe. Sputum cultures were positive in 10 cases, bronchoalveolar lavage fluid (BALF) cultures were positive in 6 cases, and next generation gene sequencings were positive in 4 cases, including 2 cases of Nocardia gelsenkii, 2 cases of Nocardia abscess, 2 cases of Nocardia stellate, 1 case of Nocardia mexicana, 1 case of Nocardia otitis caviae, and 9 cases of undetermined Nocardia. There were 3 cases of Klebsiella pneumoniae, 2 cases of Pseudomonas aeruginosa and 2 cases of Aspergillus. The symptoms and imaging of all patients were improved after anti Nocardia therapy. Conclusions: Bronchiectasis combined with nocardiosis is more common in middle-aged and elderly women without smoking, which is similar to the clinical manifestations of Lady Windermere syndrome. Bronchiectasis often involves the left lower lobe, right middle lobe and left lingual lobe. Nocardia infection might further precipitate the initiation and progression of bronchiectasis.
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[Clinical value of carbon nanoparticles tracer in gastric cancer surgery to increase the number of lymph nodes retrieval]. ZHONGHUA WEI CHANG WAI KE ZA ZHI = CHINESE JOURNAL OF GASTROINTESTINAL SURGERY 2020; 23:984-989. [PMID: 33053994 DOI: 10.3760/cma.j.cn.441530-20191031-00469] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Objective: To investigate the clinical value of carbon nanoparticles zonal tracer technique in lymph node retrieval of gastric cancer (GC). Methods: A retrospective cohort study was carried out. Clinicopathological data of GC patients who underwent radical D2 resection with carbon nanoparticles tracer in The First Affiliated Hospital of Hainan Medical University and Hainan Cancer Hospital from December 2015 and February 2019 were collected. Those with postoperative pathology of T1-2, Borrmann IV type GC, distant metastasis, preoperative neoadjuvant chemotherapy and incomplete data were excluded. A total of 181 patients were enrolled in this study, including 113 cases from the First Affiliated Hospital of Hainan Medical University and 68 cases from Hainan Cancer Hospital. Patients were categorized into two groups based on the methods of carbon nanoparticles tracer: zonal tracer group and traditional tracer group. In the traditional tracer group, 0.1-0.3 ml of carbon nanoparticle was injected subserously at the upper, lower, left and right 4 injection points 0.5 cm away from the edge of the tumor in the normal serous membrane. In the zonal tracer group, on the basis of the traditional tracer group, 0.1-0.3 ml of carbon nanoparticle was injected subserously at the first branch of the suprapyloric right gastric artery into the stomach, the first branch of the subpyloric right gastroepiploic artery into the stomach, the first branch of the minor curvature left gastric artery into the stomach and the first branch of the greater curvature left gastroepiploic artery into the stomach, respectively. The display of lymphatic vessels in each location and lymph nodes in each group by the tracing method was observed. The number of black-stained lymph nodes, the black staining rate of lymph nodes, the total number of detected lymph nodes, the total number of positive lymph nodes, and the metastatic rate of lymph node were compared between the two groups. Results: Eighty-nine patients were assigned to zonal tracer group, and 92 patients to traditional tracer group. There were no significant differences in baseline information between the two groups (all P>0.05). The median number of black-stained lymph nodes (median: 25.0 vs. 13.5, Z=-7.158, P<0.001) and the black staining rate of lymph nodes [(70.8±12.0)% vs. (47.1±15.7)%, t=11.399, P<0.001) in the zonal tracer group were significantly higher than those in the traditional tracer group. The total detected number of lymph nodes (37.5±11.5 vs. 29.6±11.8, t=4.581, P<0.001) and the total number of negative lymph nodes (31.3±12.5 vs. 24.9±11.1, t=3.621, P<0.001) were significantly higher in the zonal tracer group than those in the traditional tracer group. There were no significant differences in the total number of positive lymph nodes (median: 4.0 vs. 3.0, Z=-1.485, P=0.137), lymph node metastatic rate [78.7% (70/89) vs. 72.8% (67/92), χ(2)=0.834, P=0.361] and metastatic degree [median: 11% vs. 10%, Z=-0.483, P=0.629] between the two groups. Conclusion: The carbon nanoparticles zonal tracer method can increase the black-staining rate of lymph nodes and the detected number of lymph nodes, thus improving the accuracy of gastric cancer staging.
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[Clinical features of 2019 novel coronavirus pneumonia in the early stage from a fever clinic in Beijing]. ZHONGHUA JIE HE HE HU XI ZA ZHI = ZHONGHUA JIEHE HE HUXI ZAZHI = CHINESE JOURNAL OF TUBERCULOSIS AND RESPIRATORY DISEASES 2020; 43:215-218. [PMID: 32164091 DOI: 10.3760/cma.j.issn.1001-0939.2020.03.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To summarize and analyze the clinical and imaging characteristics of patients with 2019 novel coronavirus pneumonia in the early stage in Beijing. Methods: A retrospective analysis of clinical and imaging data of 9 patients with 2019 novel coronavirus infection diagnosed in one fever clinicic in Beijing from January 18, 2020 to February 3, 2020. Results: 5 male and 4 female was included in those 9 patients, whose median age was 36 years, and the age range from 15 to 49 years. 8 of these patients had no underlying disease and one suffered from diabetes. 7 patients had a history of travel to Wuhan City or Hubei Province, and one patient was a medical staff. Two family clustered was found. The incubation period was 1 to 6 days. The clinical manifestations were fever in 8 cases (8/9) , dry cough in 5 cases (5/9) , pharyngalgia in 4 cases (4/9) , fatigue in 4 cases (4/9) , body soreness in 4 cases (4/9) , and blocked or watery nose in 1 case (1/9) . Six patients (6/9) had abnormal cell peripheral blood, of which 3 (3/9) had an increased monocyte count, 2 (2/9) had a reduced lymphocyte, and 1 (1/9) had an increased leukocyte count, while the 3 patients had normal cell blood routines. The median of CRP was 16.3 mg/L, including 5 patients with slightly elevated (5/9) , 4 patients with normal values (4/9) . the results of procalcitonin test were negative in5 patients. Three patients were examined by chest X-ray examination, one of which was normal, one case showed infiltrates of right upper lung, and another showed in right lower lung. All patients underwent chest HRCT. And 7 cases (7/9) showed multiple ground glass exudation, including 5 cases (5/7) involved bilateral lungs, 2 cases (2/7) involved unilateral lung, 3 cases (3/7) with patchy consolidation, and 2 cases (2/9) showed no abnormality. Conclusions: The patents with 2019 novel coronavirus pneumonia in this study generally have an epidemiological history. The clinical manifestations are fever and cough. Peripheral white blood cell counts were most normal And PCT were all negative. Chest HRCT manifested as multiple ground-glass opacities with partly consolidation. Some patients had normal chest radiographs but HRCT showed pneumonia. Some patients had no pneumonia on chest HRCT.
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[Clinical features of 2019 novel coronavirus pneumonia in the early stage from a fever clinic in Beijing]. ZHONGHUA JIE HE HE HU XI ZA ZHI = ZHONGHUA JIEHE HE HUXI ZAZHI = CHINESE JOURNAL OF TUBERCULOSIS AND RESPIRATORY DISEASES 2020; 43:E013. [PMID: 32061066 DOI: 10.3760/cma.j.issn.1001-0939.2020.0013] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Objective: To summarize and analyze the clinical and imaging characteristics of patients with 2019 novel coronavirus pneumonia in the early stage in Beijing. Methods: A retrospective analysis of clinical and imaging data of 9 patients with 2019 novel coronavirus infection diagnosed in one fever clinicic in Beijing from January 18, 2020 to February 3, 2020. Results: 5 male and 4 female was included in those 9 patients, whose median age was 36 years, and the age range from 15 to 49 years. 8 of these patients had no underlying disease and one suffered from diabetes. 7 patients had a history of travel to Wuhan City or Hubei Province, and one patient was a medical staff. Two family clustered was found. The incubation period was 1 to 6 days. The clinical manifestations were fever in 8 cases (8/9) , dry cough in 5 cases (5/9) , pharyngalgia in 4 cases (4/9) , fatigue in 4 cases (4/9) , body soreness in 4 cases (4/9) , and blocked or watery nose in 1 case (1/9) . Six patients (6/9) had abnormal cell peripheral blood, of which 3 (3/9) had an increased monocyte count, 2 (2/9) had a reduced lymphocyte , and 1 (1/9) had an increased leukocyte count, while the 3 patients had normal cell blood routines. The median of CRP was 16.3 mg/L, including 5 patients with slightly elevated (5/9) , 4 patients with normal values (4/9) . the results of procalcitonin test were negative in5 patients. Three patients were examined by chest X-ray examination, one of which was normal, one case showed infiltrates of right upper lung, and another showed in right lower lung. All patients underwent chest HRCT. And 7 cases (7/9) showed multiple ground glass exudation, including 5 cases (5/7) involved bilateral lungs, 2 cases (2/7) involved unilateral lung, 3 cases (3/7) with patchy consolidation, and 2 cases (2/9) showed no abnormality. Conclusions: The patents with 2019 novel coronavirus pneumonia in this study generally have an epidemiological history. The clinical manifestations are fever and cough. Peripheral white blood cell counts were most normal And PCT were all negative. Chest HRCT manifested as multiple ground-glass opacities with partly consolidation. Some patients had normal chest radiographs but HRCT showed pneumonia. Some patients had no pneumonia on chest HRCT.
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[Effect of silica dust on protein oxidative injury in lung tissue of mice]. ZHONGHUA LAO DONG WEI SHENG ZHI YE BING ZA ZHI = ZHONGHUA LAODONG WEISHENG ZHIYEBING ZAZHI = CHINESE JOURNAL OF INDUSTRIAL HYGIENE AND OCCUPATIONAL DISEASES 2018; 35:709-711. [PMID: 29294535 DOI: 10.3760/cma.j.issn.1001-9391.2017.09.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To investigate the effect of silica dust on protein oxidative injury in the lung tissue of mice. Methods: A total of 60 mice were randomly divided into control group (not exposed to dust) , 2-hour group (inhalation of dust for 2 hours per day) , 4-hour group (inhalation of dust for 4 hours per day) , and 8-hour group (inhalation of dust for 8 hours per day) , with 15 mice in each group. During dust exposure, the mice were placed in a dust exposure cabinet; the dust was blown with an air blower and the concentration was maintained at 125 mg/m(3). All mice were exposed to silica dust for 3 weeks. The changes of the lung were observed after dust exposure ended, and spectrophotometry was performed to measure the activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) and protein carbonyl in the lung tissue. Results: The 2-, 4-, and 8-hour groups had marked edema, sporadic punctate hemorrhage, and nodular shadow in the lungs. Compared with the control group, the 2-, 4-, and 8-hour groups had a significant increase in lung coefficient (7.03±0.78 mg/g, 8.48±0.93 mg/g, and 8.99±0.85 mg/g vs 5.52±0.81 mg/g, P<0.05) . Compared with the control group, the 2-, 4-, and 8-hour groups had significant increases in the content of MDA (2.83±0.52, 3.94±0.65, and 4.56±0.77 nmol/mg prot vs 1.26±0.36 nmol/mg prot, P<0.05) and protein carbonyl (1.61±0.44, 1.96±0.47, and 2.20±0.58 nmol/mg prot vs 1.13±0.21 nmol/mg prot, P<0.05) in lung tissue. The 4- and 8-hour groups had a significantly lower activity of SOD than the control group (153.69±20.58 and 140.35±18.97 U/mg prot vs 186.00±25.46 U/mg prot, P<0.05) . Conclusions: Silica dust may lead to protein oxidative injury in the lung tissue of mice, which might play an important role in lung injury.
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In Reply to the Letter to the Editor Regarding "Percutaneous Full-Endoscopic Anterior Transcorporeal Procedure for Cervical Disc Herniation: A Novel Procedure and Early Follow-Up Study". World Neurosurg 2018; 118:386. [PMID: 30248814 DOI: 10.1016/j.wneu.2018.07.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 07/04/2018] [Indexed: 10/28/2022]
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Percutaneous Full-Endoscopic Anterior Transcorporeal Procedure for Cervical Disc Herniation: A Novel Procedure and Early Follow-Up Study. World Neurosurg 2018; 112:e23-e30. [DOI: 10.1016/j.wneu.2017.12.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 11/29/2017] [Accepted: 12/01/2017] [Indexed: 11/30/2022]
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Clinical Observation of Posterior Percutaneous Full-Endoscopic Cervical Foraminotomy as a Treatment for Osseous Foraminal Stenosis. World Neurosurg 2017; 106:945-952. [DOI: 10.1016/j.wneu.2017.07.085] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 07/15/2017] [Accepted: 07/15/2017] [Indexed: 10/19/2022]
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Slater Insulator in Iridate Perovskites with Strong Spin-Orbit Coupling. PHYSICAL REVIEW LETTERS 2016; 117:176603. [PMID: 27824456 DOI: 10.1103/physrevlett.117.176603] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Indexed: 06/06/2023]
Abstract
The perovskite SrIrO_{3} is an exotic narrow-band metal owing to a confluence of the strengths of the spin-orbit coupling (SOC) and the electron-electron correlations. It has been proposed that topological and magnetic insulating phases can be achieved by tuning the SOC, Hubbard interactions, and/or lattice symmetry. Here, we report that the substitution of nonmagnetic, isovalent Sn^{4+} for Ir^{4+} in the SrIr_{1-x}Sn_{x}O_{3} perovskites synthesized under high pressure leads to a metal-insulator transition to an antiferromagnetic (AF) phase at T_{N}≥225 K. The continuous change of the cell volume as detected by x-ray diffraction and the λ-shape transition of the specific heat on cooling through T_{N} demonstrate that the metal-insulator transition is of second order. Neutron powder diffraction results indicate that the Sn substitution enlarges an octahedral-site distortion that reduces the SOC relative to the spin-spin exchange interaction and results in the type-G AF spin ordering below T_{N}. Measurement of high-temperature magnetic susceptibility shows the evolution of magnetic coupling in the paramagnetic phase typical of weak itinerant-electron magnetism in the Sn-substituted samples. A reduced structural symmetry in the magnetically ordered phase leads to an electron gap opening at the Brillouin zone boundary below T_{N} in the same way as proposed by Slater.
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An X-ray Raman spectrometer for EXAFS studies on minerals: bent Laue spectrometer with 20 keV X-rays. JOURNAL OF SYNCHROTRON RADIATION 2013; 20:266-271. [PMID: 23412483 DOI: 10.1107/s0909049512048789] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Accepted: 11/27/2012] [Indexed: 06/01/2023]
Abstract
An X-ray Raman spectrometer for studies of local structures in minerals is discussed. Contrary to widely adopted back-scattering spectrometers using ≤10 keV X-rays, a spectrometer utilizing ~20 keV X-rays and a bent Laue analyzer is proposed. The 20 keV photons penetrate mineral samples much more deeply than 10 keV photons, so that high intensity is obtained owing to an enhancement of the scattering volume. Furthermore, a bent Laue analyzer provides a wide band-pass and a high reflectivity, leading to a much enhanced integrated intensity. A prototype spectrometer has been constructed and performance tests carried out. The oxygen K-edge in SiO(2) glass and crystal (α-quartz) has been measured with energy resolutions of 4 eV (EXAFS mode) and 1.3 eV (XANES mode). Unlike methods previously adopted, it is proposed to determine the pre-edge curve based on a theoretical Compton profile and a Monte Carlo multiple-scattering simulation before extracting EXAFS features. It is shown that the obtained EXAFS features are reproduced fairly well by a cluster model with a minimal set of fitting parameters. The spectrometer and the data processing proposed here are readily applicable to high-pressure studies.
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Determining the in-plane orientation of the ground-state orbital of CeCu2Si2. PHYSICAL REVIEW LETTERS 2012; 109:046401. [PMID: 23006099 DOI: 10.1103/physrevlett.109.046401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Indexed: 06/01/2023]
Abstract
We have successfully determined the hitherto unknown sign of the B(4)(4) Stevens crystal-field parameter of the tetragonal heavy-fermion compound CeCu(2)Si(2) using vector q-dependent nonresonant inelastic x-ray scattering experiments at the cerium N(4,5) edge. The observed difference between the two different directions, q∥[100] and q∥[110], is due to the anisotropy of the crystal-field ground state in the (001) plane and is observable only because of the utilization of higher than dipole transitions possible in nonresonant inelastic x-ray scattering. This approach allows us to go beyond the specific limitations of dc magnetic susceptibility, inelastic neutron scattering, and soft x-ray spectroscopy, and provides us with a reliable information about the orbital state of the 4f electrons relevant for the quantitative modeling of the quasiparticles and their interactions in heavy-fermion systems.
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Multiple-wave diffraction in high energy resolution back-reflecting x-ray optics. PHYSICAL REVIEW LETTERS 2011; 107:155503. [PMID: 22107300 DOI: 10.1103/physrevlett.107.155503] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Indexed: 05/31/2023]
Abstract
We have studied the effects of multiple-wave diffraction in a novel optical scheme recently published by Shvyd'ko et al. utilizing Bragg diffraction of x rays in backscattering geometry from asymmetrically cut crystals for achieving energy resolutions beyond the intrinsic width of the Bragg reflection. By numerical simulations based on dynamic x-ray diffraction and by experimentation involving two-dimensional angular scans of the back-reflecting crystal, multiple-wave diffraction was found to contribute up to several tens percent loss of efficiency but can be avoided without degrading the energy resolution of the original scheme by careful choice of azimuthal orientation of the diffracting crystal surface and by tilting of the crystal perpendicular to the dispersion plane.
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Cellular immunologic response to primary cryoablation of C6 gliomas in rats. Technol Cancer Res Treat 2011; 10:95-100. [PMID: 21214292 DOI: 10.7785/tcrt.2012.500183] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The immunological consequences of cryoablation for gliomas are largely unknown. cryoablation is an attractive therapeutic option for tumors due to its minimally invasive nature. cryoablation is also potentially immunogenic. With an aim to explore changes in cellular immunity following argon-helium cryosurgery, we established Wistar rat models bearing subcutaneous C6 glioma and divided the rats into the normal control (30 rats), sham-operated (33 rats), surgical resection (30 rats), and cryosurgery (33 rats) groups with corresponding treatments. The tumor cell morphology was observed, and changes in the T lymphocyte subset and NK lymphocyte subset and the ratio of Th1/Th2 were assessed with flow cytometry following the cryosurgery. The results showed that subcutaneous tumor implantation was successful in all cases and this was confirmed histologically. Compared with surgical resection that caused significant reduction in CD3(+), CD4(+), CD14(+), CD16+56 cell percentages, cryosurgery resulted in significantly increased percentages of CD3(+), CD4(+), CD14(+), CD16+56 cells (P < 0.05) with a increase of the Th1/Th2 ratio 7 days after the operation. These results demonstrate that in addition to tumor cell destruction, cryosurgery also results in enhanced cellular immunity, suggesting the great potential of argon-helium cryosurgery in clinical management of gliomas.
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Structural and microscopic relaxations in glycerol: An inelastic x-ray scattering study. J Chem Phys 2011; 134:184502. [DOI: 10.1063/1.3587104] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
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Anomalous angular dependence of the dynamic structure factor near Bragg reflections: graphite. PHYSICAL REVIEW LETTERS 2008; 101:266406. [PMID: 19437659 DOI: 10.1103/physrevlett.101.266406] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The electron energy-loss function of graphite is studied for momentum transfers q beyond the first Brillouin zone. We find that near Bragg reflections the spectra can change drastically for very small variations in q. The effect is investigated by means of first principle calculations in the random phase approximation and confirmed by inelastic x-ray scattering measurements of the dynamic structure factor S(q, omega). We demonstrate that this effect is governed by crystal local field effects and the stacking of graphite. It is traced back to a strong coupling between excitations at small and large momentum transfers.
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Pressure-induced valence anomaly in TmTe probed by resonant inelastic X-ray scattering. PHYSICAL REVIEW LETTERS 2008; 101:127401. [PMID: 18851408 DOI: 10.1103/physrevlett.101.127401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2007] [Revised: 12/09/2007] [Indexed: 05/26/2023]
Abstract
The pressure-induced valence transition in TmTe was investigated by resonant inelastic x-ray scattering at the Tm L3 edge, a powerful probe of the rare-earth valent state. The data are analyzed within the Anderson impurity model which yields key parameters such as the Tm 4f-5d hybridization. In addition to the general tendency of the f electrons towards delocalization, we find a plateau in both the Tm valence and hybridization pressure dependences between 4.3 and 6.5 GPa which is interpreted in terms of an n-channel Kondo (NCK) screening process. This behavior is at odds with the usually continuous, single-channel Kondo-like f delocalization while being supported by the seminal calculations of the NCK temperature in Tm ion by Saso et al. Our study raises the interesting possibility that an NCK effect realized in a compressed mixed-valent f system could impede the concomitant electron delocalization.
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Inelastic x-ray scattering study of exciton properties in an organic molecular crystal. PHYSICAL REVIEW LETTERS 2007; 98:036404. [PMID: 17358703 DOI: 10.1103/physrevlett.98.036404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2006] [Indexed: 05/14/2023]
Abstract
Excitons in a complex organic molecular crystal were studied by inelastic x-ray scattering (IXS) for the first time. The dynamic dielectric response function is measured over a large momentum transfer region, from which an exciton dispersion of 130 meV is observed. Semiempirical quantum chemical calculations reproduce well the momentum dependence of the measured dynamic dielectric responses, and thus unambiguously indicate that the lowest Frenkel exciton is confined within a fraction of the complex molecule. Our results demonstrate that IXS is a powerful tool for studying excitons in complex organic molecular systems. Besides the energy position, the IXS spectra provide a stringent test on the validity of the theoretically calculated exciton wave functions.
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Low-energy charge-density excitations in MgB2: Striking interplay between single-particle and collective behavior for large momenta. PHYSICAL REVIEW LETTERS 2006; 97:176402. [PMID: 17155487 DOI: 10.1103/physrevlett.97.176402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2006] [Indexed: 05/12/2023]
Abstract
A sharp feature in the charge-density excitation spectra of single-crystal MgB2, displaying a remarkable cosinelike, periodic energy dispersion with momentum transfer (q) along the c* axis, has been observed for the first time by high-resolution nonresonant inelastic x-ray scattering (NIXS). Time-dependent density-functional theory calculations show that the physics underlying the NIXS data is strong coupling between single-particle and collective degrees of freedom, mediated by large crystal local-field effects. As a result, the small-q collective mode residing in the single-particle excitation gap of the B pi bands reappears periodically in higher Brillouin zones. The NIXS data thus embody a novel signature of the layered electronic structure of MgB2.
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Localized and delocalized excitons: resonant inelastic x-ray scattering in La(2-x)Sr(x)NiO4 and La(2-x)Sr(x)CuO4. PHYSICAL REVIEW LETTERS 2006; 96:157004. [PMID: 16712189 DOI: 10.1103/physrevlett.96.157004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2005] [Indexed: 05/09/2023]
Abstract
The dynamics of doped charge in an antiferromagnetic lattice is central to the description of the insulator-metal transition that occurs on doping the parent high T(c) compounds. In this work we use high resolution resonant inelastic x-ray scattering to investigate the dynamics of the charge-transfer exciton by measuring its energy dispersion in two prototype compounds, La2CuO4 and La2NiO4. We show that this behavior is radically different in the cuprate with respect to a system known to exhibit strong polaronic behavior, namely, the nickelate: the exciton is mobile in the cuprate while it is well localized in the nickelate. Using a simple Wannier-Mott model we can estimate the total hole plus electron effective mass in the cuprate to be 3.5 +/- 0.3 m(e) which would exclude strong localization in the undoped cuprate.
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Nichtinvasives MRT differenziert zwischen symptomatischen und asymptomatischen arteriosklerotischen Plaques der Karotiden. ROFO-FORTSCHR RONTG 2005. [DOI: 10.1055/s-2005-867935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Ordering of hydrogen bonds in high-pressure low-temperature H2O. PHYSICAL REVIEW LETTERS 2005; 94:025502. [PMID: 15698189 DOI: 10.1103/physrevlett.94.025502] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2004] [Indexed: 05/24/2023]
Abstract
The near K-edge structure of oxygen in liquid water and ices III, II, and IX at 0.25 GPa and several low temperatures down to 4 K has been studied using inelastic x-ray scattering at 9884.7 eV with a total energy resolution of 305 and 175 meV. A marked decrease of the preedge intensity from the liquid phase and ice III to ices II and IX is attributed to ordering of the hydrogen bonds in the proton-ordered lattice of the latter phases. Density functional theory calculations including the influence of the Madelung potential of the ice IX crystal correctly account for the remaining preedge feature. Furthermore, we obtain spectroscopic evidence suggesting a possible new phase of ice at temperatures between 4 and 50 K.
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Carotid plaque composition differs between ethno-racial groups: an MRI pilot study comparing mainland Chinese and American Caucasian patients. Arterioscler Thromb Vasc Biol 2005; 25:611-6. [PMID: 15653565 DOI: 10.1161/01.atv.0000155965.54679.79] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Ethnicity-based research may identify new clues to the pathogenesis of atherosclerotic disease. Therefore, we sought to determine whether carotid lesions differ between 20 Chinese and 20 Caucasian Americans by MRI. METHODS AND RESULTS Inclusion criteria were >50% stenosis as measured by duplex ultrasound and recent symptoms attributed to carotid artery disease. The patients were imaged in 2 centers (Beijing, China and Seattle, Wash) using a standardized protocol. Both carotid arteries were reviewed quantitatively (lumen, wall, outer wall, tissue components) and morphologically (lesion types, fibrous cap status). Significant differences between the Chinese and Americans were found for the mean size of the lipid/necrotic core (13.6 versus 7.8 mm2; P=0.002), percentage of slices with calcified type VII lesions (1.6 versus 12.4%; P=0.03), and percentage of slices with early type III lesions (19.3 versus 9.3%; P=0.02). Furthermore, the mean outer wall area in the common carotid artery was larger in the Chinese population (P=0.007). CONCLUSIONS This pilot study suggests that composition and morphology of atherosclerotic lesions in symptomatic carotid disease differ between ethno-racial groups. Quantitative MRI-based review of carotid atherosclerosis comparing plaque morphology and composition between ethno-racial groups is feasible, and future MRI studies may improve our understanding of the pathophysiology of this disease.
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[The development of a simulated experimental system on humoral integrated parameter tests controlled by a microcomputer]. ZHONGGUO YI LIAO QI XIE ZA ZHI = CHINESE JOURNAL OF MEDICAL INSTRUMENTATION 2001; 25:88-90. [PMID: 12583148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A simulated experimental system on humoral integrated parameter tests controlled by a microcomputer is developed for overcoming hard training in maintenance technical skill. This paper describes its structure, characteristics, functions and the prospects of its applications.
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Abstract
PURPOSE Our goal was to evaluate the presence and the significance of the air bronchogram sign in solitary pulmonary lesions (SPL) on CT. METHOD One hundred thirty-two patients with SPL who underwent chest CT scans and had histological diagnosis were studied retrospectively. We reviewed all chest CT scans to assess for the presence of the air bronchogram sign in the SPL and recorded the distribution of this sign in malignant and benign lesions. The morphology of the aerated bronchi in the lesion and its significance in differential diagnosis were also evaluated. RESULTS Of 17 cases of benign lesions, only 1 (5.9%) had an air bronchogram; of 115 lung cancers, 33 (28.7%) had this sign (p < 0.05). The encased bronchi exhibited four morphologic patterns: normal, tortuous, ectatic, and cut-off. The morphology of the bronchus in the benign lesion was normal. However, bronchi in malignant lesions displayed all four types of morphology. The air bronchogram sign was seen in all histologic types of lung cancer (squamous cell 10, adenocarcinoma 9, bronchioloalveolar cell 12, small cell 1, non-small cell 1). Lesions of different sizes were noted to have air bronchograms, including those < 2 cm in diameter. CONCLUSION The CT air bronchogram sign in SPL is significantly more common in malignant than in benign lesions. The sign is seen in all lung cancer cell types and demonstrates varied bronchial morphology.
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Soft-x-ray lasing at 32.6 nm in Ne-like Ti ions driven by 40 J of energy from two 650-ps laser pulses. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1996; 53:3640-3646. [PMID: 9913308 DOI: 10.1103/physreva.53.3640] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Angle-resolved photoemission from a GaAs (1-bar 1-bar 1-bar)-2 x 2 surface: Off-normal emission study. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:4729-4733. [PMID: 9984033 DOI: 10.1103/physrevb.53.4729] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Cross-sectional assessment of renal function in the inhabitants of a cadmium-polluted area. ANNALS OF CLINICAL AND LABORATORY SCIENCE 1995; 25:493-503. [PMID: 8572558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
To understand the development of cadmium (Cd)-induced renal tubular dysfunction, cross-sectional assessment of renal function in the inhabitants of the Cd-polluted Jinzu River basin in Toyama, Japan, was carried out. Sixty-seven men and 78 women, aged 56 to 71 years whose urinary beta 2-microglobulin (beta 2-m) exceeded 1,000 micrograms/g creatinine, were examined and divided into five groups according to their values of fractional excretion of beta 2-m (FE beta 2-m). Comparisons were made between six groups including the inhabitants of a non-polluted area as a reference group. Significantly increased values of fractional excretion of urate (FEUA), calcium (FECa), sodium (FENa), and chloride (FECl), serum creatinine and beta 2-m, and urinary protein were detected even in the subjects with FE beta 2-m level below 1 percent compared with the reference group. Fractional phosphate reabsorption (percent TRP) was significantly decreased in the subjects with FE beta 2-m level above 10 percent. Creatinine clearance (CCr) decreased with increase in FE beta 2-m, and the subjects with FE beta 2-m above 30 percent showed significantly decreased CCr values compared to those with FE beta 2-m below 30 percent. In summary, FEUA, FECa, FENa, and FECl, as well as low-molecular-weight proteins such as beta 2-m, are increased in the early stage of Cd-induced renal tubular dysfunction. Although percent TRP was maintained by the decreased CCr, there was a marked decrease in percent TRP in subjects with progressive stage showing FE beta 2-m level above 10 percent. No sex difference in renal tubular dysfunction was found in this cross-sectional study.
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Valence electronic structure of polycrystalline SiC as observed by (e,2e) spectroscopy. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 51:3449-3457. [PMID: 9979152 DOI: 10.1103/physrevb.51.3449] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Relation between lattice order and energy-resolved momentum densities in carbon films. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 51:1866-1873. [PMID: 9978910 DOI: 10.1103/physrevb.51.1866] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Angle-resolved photoemission from a GaAs(1-bar1-bar1-bar)-2 x 2 surface: Normal emission study. PHYSICAL REVIEW. B, CONDENSED MATTER 1993; 48:18079-18087. [PMID: 10008446 DOI: 10.1103/physrevb.48.18079] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Air bronchogram in differential diagnosis of small peripheral lung cancers on CT image. Chin Med J (Engl) 1993; 106:357-60. [PMID: 8404278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The computed tomographic (CT) images of 52 patients of small peripheral lung nodule < 3 cm proved pathologically were reviewed. Air bronchogram (AB) was found in 14 nodules on thin-section CT images, in which well or moderately differentiated small adenocarcinomas were only seen with lipidic growth. Squamous-cell, large-cell carcinomas and small benign lung nodules had no AB sign both on CT image and in pathologic specimens.
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Abstract
To investigate the effect of exposure to tobacco smoke (TS) on the development of irradiation-induced pneumonitis in rats, five groups of animals were investigated including controls (C), tobacco smoke exposed (S), irradiated (RNS) and irradiated and tobacco smoke exposed (RS). An additional group (RS/NS) was exposed to tobacco before irradiation but not afterwards. Rats were exposed to diluted mainstream cigarette smoke at a concentration of about 0.4 mg/l in a nose-only exposure system for 1/day, 5 days/week for 10 weeks. Exposure to TS started 3 weeks before irradiation in which the basal one-third of both lungs was exposed to a single dose of 28 Gy. In previous studies this dose had been shown to cause significant pneumonitis. All the animals were killed at 7 weeks after irradiation. Examination of the morphology of lung sections showed less pulmonary inflammation in the RS group than in the RNS group. This was also reflected in the results of bronchoalveolar lavage (BAL) which showed a decline in cell recovery and a marked decrease in the numbers of mast cells and neutrophils in the RS rats compared with the RNS animals. The concentration of hyaluronan in lavage fluid was increased in the RNS and RS/NS group while no increase was found in the RS group. A marked increase in BAL protein was also seen in the RNS and RS/NS groups as compared with the RS group but all were significantly higher than in unirradiated controls. This indicates that smoking suppresses the radiation-induced inflammation but to a lesser degree affects the radiation-induced increase in membrane permeability as reflected by increased protein levels in BAL. Moreover, the marked effects on the numbers of mast cells and neutrophils in the RS group may indicate that these cells play an important role in the mechanism by which tobacco smoke modulates the effects of irradiation. When exposure to tobacco smoke was terminated immediately after irradiation (RS/NS), the inflammatory response was unaffected.
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Two-dimensional electronic structure Ei(ki||,kiperp) of GaAs(001) studied by angle-resolved photoemission. PHYSICAL REVIEW. B, CONDENSED MATTER 1992; 46:6891-6901. [PMID: 10002392 DOI: 10.1103/physrevb.46.6891] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Photoemission study of the electronic structure of a (GaAs)2/(AlAs)2 superlattice. PHYSICAL REVIEW. B, CONDENSED MATTER 1991; 44:3787-3792. [PMID: 10000006 DOI: 10.1103/physrevb.44.3787] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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