3251
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Li Q. Anesthetizing the anterior palatine nerve through the maxillary tuberosity. QUINTESSENCE INTERNATIONAL (BERLIN, GERMANY : 1985) 1989; 20:925. [PMID: 2639408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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3252
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Travers JB, Li Q, Kniss DA, Fertel RH. Identification of functional platelet-activating factor receptors in Raji lymphoblasts. THE JOURNAL OF IMMUNOLOGY 1989. [DOI: 10.4049/jimmunol.143.11.3708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
The binding and metabolism of platelet-activating factor (PAF) were characterized in Raji, a human Burkitt's lymphoma-derived cell line. Raji lymphoblasts readily metabolized PAF by deacetylation-reacylation at 37 degrees C, but not at 4 degrees C. Binding studies conducted at 4 degrees C demonstrated specific binding that reached saturation within 80 min. This binding was only partially reversible. Scatchard analysis of PAF binding data revealed a single class of PAF binding sites (17,800 +/- 3,600/cell) with a K of 2.3 +/- 0.3 nM. These high-affinity PAF binding sites were shown to be functional receptors, as 100 pM to 1 microM PAF increased free intracellular calcium in a dose-dependent manner. The dose of PAF necessary to achieve half maximal calcium mobilization response was 6.3 nM, which was in the range of the K for the receptor calculated from the binding studies. The structurally dissimilar PAF receptor antagonists CV-3988 and BN52021 inhibited the PAF-induced calcium changes at doses that competed with PAF binding. These studies provide the first evidence for a functional PAF receptor expressed on a lymphocyte cell line.
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3253
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Li Q, Thouless DJ. Localization and hopping conductivity in the quantum Hall regime. PHYSICAL REVIEW. B, CONDENSED MATTER 1989; 40:9738-9743. [PMID: 9991494 DOI: 10.1103/physrevb.40.9738] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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3254
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Li Q, Guan Z, Biagi BA, Stokes BT, Altschuld RA. Hyperthyroid adult rat cardiomyocytes. II. Single cell electrophysiology and free calcium transients. THE AMERICAN JOURNAL OF PHYSIOLOGY 1989; 257:C957-63. [PMID: 2596589 DOI: 10.1152/ajpcell.1989.257.5.c957] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The effects of hyperthyroidism on electrophysiological properties and intracellular free calcium transients in single adult rat cardiomyocytes were studied using conventional microelectrodes and time-resolved single cell fura-2 fluorescence microscopy. Under control conditions, resting membrane potentials and triggered action potentials were not different in euthyroid and hyperthyroid myocytes. Calcium transients produced by electrical stimulation, however, were markedly abbreviated in hyperthyroid myocytes. During a train of stimuli, the duration of the calcium transients at half peak amplitude (half time) was 124 +/- 14 ms at the fifth beat in hyperthyroid cells vs. 287 +/- 35 ms in euthyroid cells. Isoproterenol (1 microM) prolonged time to 50% repolarization (APD50) of the action potentials and increased the peak calcium transients in both euthyroid and hyperthyroid myocytes. It also shortened the half time of the calcium transients in euthyroid myocytes but had little effect on the half time in hyperthyroid cells. These data are consistent with the electrophysiology and mechanical performance in intact euthyroid and hyperthyroid cardiac tissues, and the intrinsic changes in hyperthyroid tissues can therefore be illustrated in single ventricular myocytes. Furthermore, the results suggest that alterations in intracellular calcium handling by sarcoplasmic reticulum may account for contractile changes of the heart induced by hyperthyroidism.
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3255
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Dugas CM, Li Q, Khan IA, Nothnagel EA. Lateral diffusion in the plasma membrane of maize protoplasts with implications for cell culture. PLANTA 1989; 179:387-396. [PMID: 24201669 DOI: 10.1007/bf00391085] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/1989] [Accepted: 06/17/1989] [Indexed: 06/02/2023]
Abstract
Plasma-membrane dynamics in live protoplasts from maize (Zea mays L.) roots were characterized and examined for relationships as to the ability of the protoplasts to synthesize new cell walls and develop to cells capable of division. The lateral diffusion-coefficients and mobile fractions of fluorescence-labeled plasma-membrane proteins and lipids were measured by fluorescence photobleaching recovery. Small but significant effects on the diffusion of membrane proteins were observed after treatments with oryzalin or amiprophosmethyl, microtubule-disrupting drugs that increased the mobile fraction, and after treatments with cytochalasins B or D, microfilament-disrupting drugs that decreased the diffusion coefficient. A number of parameters were tested for correlative effects on membrane dynamics and protoplast performance in culture. Protoplasts isolated with a cellulase preparation from Trichoderma viride showed faster membrane-protein diffusion and a lower frequency of development to cells capable of division than did protoplasts isolated with a cellulase preparation from T. reesei. Membrane proteins in maize A632, a line less capable of plant regeneration from callus, diffused with a smaller diffusion coefficient but a greater mobile fraction than did membrane proteins in maize A634, a line with greater regeneration capacity. The plasma membranes of A632 and A634 protoplasts also differed with regard to lateral-diffusion characteristics of phospholipid and sterol probes, although the presence of both rapidly and slowly diffusing lipid components indicated the apparent existence of lipid domains in both A632 and A634. The protoplasts of the two lines did not differ significantly, however, in either wall regeneration or frequency of development to cells capable of division.
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3256
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Li Q. Collective excitation spectra of one-dimensional electron systems. PHYSICAL REVIEW. B, CONDENSED MATTER 1989; 40:5860-5863. [PMID: 9992641 DOI: 10.1103/physrevb.40.5860] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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3257
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Sand O, Chen B, Li Q, Karlsen HE, Bjøro T, Haug E. Vasoactive intestinal peptide (VIP) may reduce the removal rate of cytosolic Ca2+ after transient elevations in clonal rat lactotrophs. ACTA PHYSIOLOGICA SCANDINAVICA 1989; 137:113-23. [PMID: 2552748 DOI: 10.1111/j.1748-1716.1989.tb08727.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The prolactin-producing rat anterior pituitary GH4C1 cells possess Ca2+-activated K channels which are activated by physiological elevations of the cytosolic Ca2+ concentration even at membrane potentials more negative than the normal level of about -50 mV. Whole-cell current recordings showed a marked outward tail current following depolarizing voltage steps to 0 mV from a holding potential close to the normal membrane potential. The half-time of this tail current was about 1.3 s after a 4-s depolarization step. The GH4C1 cells also possess voltage-activated Ca channels, and we conclude that this tail current is a Ca2+-activated K+ current for the following reasons: (1) The reversal potential for the tail current was close to the K+ equilibrium potential for a range of transmembrane K+ gradients. (2) The tail current was blocked by a Ca2+ antagonist, and the voltage dependence of this current closely mirrored the voltage dependence of the isolated Ca2+ current. The time-course of the decline of the tail current thus reflects the removal rate of the Ca2+ entering the cytosol through voltage-dependent Ca channels during the depolarizing voltage step. VIP stimulates prolactin secretion from GH4C1 cells, and this peptide prolonged the half-time of the tail current by about 47% in 63% of the cells. This indicates that VIP may prolong the transient cytosolic Ca2+ elevations following the action potentials in these cells. Such a mechanism might be an important factor for the control of the cytosolic Ca2+ level, and hence hormone secretion.
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3258
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Li Q, Hohl CM, Altschuld RA, Stokes BT. Energy depletion-repletion and calcium transients in single cardiomyocytes. THE AMERICAN JOURNAL OF PHYSIOLOGY 1989; 257:C427-34. [PMID: 2782386 DOI: 10.1152/ajpcell.1989.257.3.c427] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Rapid fluctuations of intracellular free calcium in single adult rat heart myocytes were monitored by time-resolved fura-2 fluorescence microscopy. Under controlled aerobic conditions (35 degrees C, pH 7.3), electrical stimulation at 0.5 Hz produced a concave negative staircase of calcium transients. When the myocytes were challenged with 3 mM amobarbital (Amytal) and 2 microM carbonyl cyanide m-chlorophenylhydrazone (CCCP) to deplete ATP, the cells became unresponsive to electrical stimulation within 1 min but responded to 10 mM caffeine with a large increase in free calcium. After the development of rigor contracture, the cellular response to caffeine was blunted. Free calcium increased at a variable rate in individual cells, reaching values of 300-1,000 nM after 15 min. When the inhibitors were removed, calcium declined toward control values, and spontaneous contractile activity and calcium transients were invariably observed. During subsequent electrical stimulation, there was a decrease in the half-widths of the calcium transients and an attenuation of the negative staircase. Parallel experiments with cells in suspension indicated that Amytal and CCCP caused ATP to fall from 27.6 +/- 1.6 to 0.7 +/- 0.2 nmol/mg protein, and the percent rod-shaped cells to fall from 70 to 0% in 5 min. Removal of the inhibitors after 15 min caused a rebound in ATP to 5.3 +/- 1.5 nmol/mg within 2 min and 6.6 +/- 1.3 nmol/mg after 10 min.
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3259
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Li Q, Soukoulis CM, Economou EN, Grest GS. Anisotropic tight-binding model for localization. PHYSICAL REVIEW. B, CONDENSED MATTER 1989; 40:2825-2830. [PMID: 9992212 DOI: 10.1103/physrevb.40.2825] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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3260
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Li Q, Xie XC. Calculated heat capacity and magnetization of two-dimensional electron systems. PHYSICAL REVIEW. B, CONDENSED MATTER 1989; 40:1381-1384. [PMID: 9991981 DOI: 10.1103/physrevb.40.1381] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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3261
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Xu Z, Cao HY, Li Q. [Protective effects of berberine on spontaneous ventricular fibrillation in dogs after myocardial infarction]. ZHONGGUO YAO LI XUE BAO = ACTA PHARMACOLOGICA SINICA 1989; 10:320-4. [PMID: 2624115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The effects of berberine (Ber 5 mg/kg iv) on ventricular tachyarrhythmias and electrophysiologic consequences in both normal and ischemic myocardium were studied in the open-chest dogs subjected to programmed electrical stimulation (PES) and intimal surface anodal direct current stimulation of the circumflex coronary artery on 5-8 d after acute myocardial infarction. Its effects were compared with procainamide (PA). Both drugs distinctly lengthened the QTc interval and the effective refractory period (ERP) of normal and infarct myocardium in both ventricles and decreased the dispersion of ERP in infarct myocardium (IDR) as well as the dispersion of ERP in left ventricle (VDR). The PES-induced ventricular tachycardia (VT) or ventricular fibrillation (VF) was prevented in 4 out of 6 Ber treated and 5 out of 6 PA treated dogs. Ber prevented spontaneous VF in 4 dogs (n = 5). PA prevented spontaneous VF in 3 dogs (n = 5). Normal saline (NS) did not prevent PES-induced VT/VF and spontaneous VF. The results suggest that Ber may be effective in preventing the onset of reentrant ventricular tachyarrhythmias and sudden coronary death after myocardial ischemic damage.
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3262
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Congote LF, Theberge J, Mazza L, Li Q. Assay for thymidine incorporation into anchorage dependent or independent cells without filtration or cell harvesting. ACTA ACUST UNITED AC 1989. [DOI: 10.1007/bf01404641] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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3263
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Li Q, Lu S, Luo JM, Liang SZ. An observation on the therapeutic effect of acupuncture in the treatment of sciatica. J TRADIT CHIN MED 1989; 9:90-2. [PMID: 2779282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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3264
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Li Q, Weschenfelder F, Meyer O, Xi X, Linker G, Geerk J. Channelling behaviour of expitaxial YBa2Cu3O7 films with various orientations. ACTA ACUST UNITED AC 1989. [DOI: 10.1016/0022-5088(89)90330-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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3265
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Li Q, Rigby KW, Rzchowski MS. Temperature-, magnetic-field-, and power-dependent microwave resistance of YBa2Cu3O7- delta. PHYSICAL REVIEW. B, CONDENSED MATTER 1989; 39:6607-6611. [PMID: 9947301 DOI: 10.1103/physrevb.39.6607] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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3266
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Li Q, Wu JQ, Ko CM. Relativistic Vlasov-Uehling-Uhlenbeck equation for nucleus-nucleus collisions. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1989; 39:849-852. [PMID: 9955273 DOI: 10.1103/physrevc.39.849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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3267
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Li Q, Li L, Kou XF, Zhang SH. [Screening of strains producing extracellular catechol 1,2-dioxygenase and fermentation conditions]. WEI SHENG WU XUE BAO = ACTA MICROBIOLOGICA SINICA 1989; 29:39-44. [PMID: 2800537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Two strains of Pseudomonus sp. having the extracellular catechol 1, 2-dioxygenase activity were selected from 112 bacterial strains. The conditions for enzyme production of the strains were examined. The optimal temperature and pH for enzyme formation were 30 degrees C and pH 6.8-7.0 respectively. Enzyme formation was enhanced by sodium benzoate, and was markedly inhibited by glucose, maltose and glycerol. Ammoniacal nitrogen sources were essential for cell growth and enzyme production. Sodium succinate was an effective inducer for enzyme formation. When the organism was grown in 0.15% sodium benzoate medium (pH 6.8-7.0) at 30 degrees C for 72 hours, about 10 units of catechol 1,2 dioxygenase per ml was obtained.
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3268
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Li Q, Nothnagel EA. Fluorescence and Delayed Light Emission from Mesophyll and Bundle Sheath Cells in Leaves of Normal and Salt-Treated Panicum miliaceum. PLANT PHYSIOLOGY 1989; 89:211-9. [PMID: 16666517 PMCID: PMC1055821 DOI: 10.1104/pp.89.1.211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
A modified fluorescence microscope system was used to measure chlorophyll fluorescence and delayed light emission from mesophyll and bundle sheath cells in situ in fresh-cut sections from leaves of Panicum miliaceum L. The fluorescence rise in 3-(3,4-dichlorophenyl)-1, 1-dimethylurea (DCMU)-treated leaves and the slow fluorescence kinetics in untreated leaves show that mesophyll chloroplasts have larger photosystem II unit sizes than do bundle sheath chloroplasts. The larger photosystem II units imply more efficient noncyclic electron transport in mesophyll chloroplasts. Quenching of slow fluorescence also differs between the cell types with mesophyll chloroplasts showing complex kinetics and bundle sheath chloroplasts showing a relatively simple decline. Properties of the photosynthetic system were also investigated in leaves from plants grown in soil containing elevated NaCl levels. As judged by changes in both fluorescence kinetics in DCMU-treated leaves and delayed light emission in leaves not exposed to DCMU, salinity altered photosystem II in bundle sheath cells but not in mesophyll cells. This result may indicate different ionic distributions in the two cell types or, alternatively, different responses of the two chloroplast types to environmental change.
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3269
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Liu JZ, Gao QS, Jiang Z, Liang CC, Yang KG, Wu GY, Long GF, Li Q, Zhang J, Deng B. Studies of beta-thalassemia mutations in families living in three provinces in southern China. Hemoglobin 1989; 13:585-95. [PMID: 2606726 DOI: 10.3109/03630268908993109] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
beta-Thalassemia is a common disease in Southern China and 10 different mutations or frameshifts are responsible for most types of beta-thalassemia in this area. We studied 126 chromosomes of 80 beta-thalassemia patients from the Guangxi, Guangdong, and Sichuan Provinces using the polymerase chain reaction followed by dot-blot hybridization with specific oligonucleotide probes. The most common mutation in the three provinces is the frameshift at codons 41-42, followed by the A----T mutation at codon 17. The A----G mutation at nt -29 of the promoter is common in Sichuan but not in the other two provinces. Three mutations (T----C at nt -30; G----T at IVS-I-1, and G----C at IVS-I-5) were not observed. These data were used to initiate a prenatal diagnosis program using the same techniques for identification. Eleven fetuses at risk for beta-thalassemia have been diagnosed.
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3270
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Wienbeck M, Li Q. Cisapride in gastro-oesophageal reflux disease: effects on oesophageal motility and intra-oesophageal pH. SCANDINAVIAN JOURNAL OF GASTROENTEROLOGY. SUPPLEMENT 1989; 165:13-8; discussion 27-8. [PMID: 2690320 DOI: 10.3109/00365528909091226] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Since gastro-oesophageal reflux disease is due to disturbances of oesophageal motility, motor and pH measurements are an important means to test a new anti-reflux drug, cisapride. In oesophageal manometry cisapride increased the pressure of the lower oesophageal sphincter in healthy volunteers and patients, and in the majority of studies it also strengthened the amplitude of oesophageal contractions. Cisapride lowered the total duration of acid exposure in the lower oesophagus in both volunteers and reflux patients. Thus cisapride may be useful in the treatment of gastro-oesophageal reflux disease.
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3271
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Li Q, Soukoulis CM, Pnevmatikos S, Economou EN. Scattering properties of solitons in nonlinear disordered chains. PHYSICAL REVIEW. B, CONDENSED MATTER 1988; 38:11888-11891. [PMID: 9946093 DOI: 10.1103/physrevb.38.11888] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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3272
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Soukoulis CM, Grest GS, Li Q. Metal-insulator transition in random superconducting networks. PHYSICAL REVIEW. B, CONDENSED MATTER 1988; 38:12000-12003. [PMID: 9946125 DOI: 10.1103/physrevb.38.12000] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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3273
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Li Q. [Immunohistochemical study of alpha-1-antichymotrypsin and GFAP in glioma]. ZHONGHUA ZHONG LIU ZA ZHI [CHINESE JOURNAL OF ONCOLOGY] 1988; 10:427-9. [PMID: 3266933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
GFAP is a specific antigen of glial element, but Alpha-1-antichymotrypsin has not been reported in the literature Alpha-1-antichymotrypsin was guided by GFAP using PAP method to the astrocytes of 137 gliomas. 120 (87%) gliomas were positive for Alpha-1-antichymotrypsin. Of these 120 gliomas, 86 (72%) gave diffuse distribution, 17 (14%) gave focal distribution, and 17 (14%) gave scattered distributions. Alpha-1-antichymotrypsin in glioma tissue may be an important tumor marker for diagnosis.
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3274
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Wienbeck M, Karaus M, Li Q. [Practical significance of gastrointestinal motility disorders]. ZEITSCHRIFT FUR GASTROENTEROLOGIE 1988; 26 Suppl 4:1-3. [PMID: 3070977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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3275
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Li Q, Ornston LN. [Purification and properties of beta-ketoadipyl-coenzyme A thiolase from Pseudomonas putida]. WEI SHENG WU XUE BAO = ACTA MICROBIOLOGICA SINICA 1988; 28:235-41. [PMID: 3250096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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3276
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Li Q. [A comparison of human insulin and porcine insulin on biological-specific activities]. SHENG LI KE XUE JIN ZHAN [PROGRESS IN PHYSIOLOGY] 1988; 19:264-7. [PMID: 3074496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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3277
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Zhao CY, Yang Y, Li H, Zheng XL, Yang FH, Li Q. [Study on the inhibition of solid form of S-180 through water soluble polysaccharides from Flammulina velutipes]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 1988; 19:146-9. [PMID: 3198094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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3278
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Li Q, Soukoulis CM, Economou EN. Universal behavior near the band edges for disordered systems: Numerical and coherent-potential-approximation studies. PHYSICAL REVIEW. B, CONDENSED MATTER 1988; 37:8289-8297. [PMID: 9944165 DOI: 10.1103/physrevb.37.8289] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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3279
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Ko CM, Li Q. Relativistic Vlasov-Uehling-Uhlenbeck model for heavy-ion collisions. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1988; 37:2270-2273. [PMID: 9954707 DOI: 10.1103/physrevc.37.2270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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3280
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Li Q. [Immunological approach to vernal keratoconjunctivitis]. [ZHONGHUA YAN KE ZA ZHI] CHINESE JOURNAL OF OPHTHALMOLOGY 1988; 24:94-7. [PMID: 3143535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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3281
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Li Q, Pnevmatikos S, Economou EN, Soukoulis CM. Lattice-soliton scattering in nonlinear atomic chains. PHYSICAL REVIEW. B, CONDENSED MATTER 1988; 37:3534-3541. [PMID: 9944950 DOI: 10.1103/physrevb.37.3534] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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3282
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Li Q, Nothnagel EA. Absence of Variable Fluorescence from Guard Cell Chloroplasts of Stenotaphrum secundatum. PLANT PHYSIOLOGY 1988; 86:429-34. [PMID: 16665925 PMCID: PMC1054501 DOI: 10.1104/pp.86.2.429] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The lack of detectable variable fluorescence from guard cell chloroplasts in both the albino and green portions of variegated leaves of St. Augustine grass (Stenotaphrum secundatum var variegatum A.S. Hitchc.) is reported. Fluorescence was measured either with a highly sensitive, modified fluorescence microscope which was capable of recording fluorescence induction curves from single chloroplasts, or with a spectrofluorometer. Both fast and slow fluorescence transients from S. secundatum guard cells showed a rapid rise and then remained at a steady level. Neither variable fluorescence increase (induction) nor decrease (quenching), properties normally associated with photosystem II, was observed from these chloroplasts. These fluorescence kinetics did not change either with alterations of the specimen preparation procedure or with alterations of the excitation light intensities and wavelengths. These results indicate that guard cell chloroplasts in this variety of S. secundatum do not conduct normal photosystem II electron transport. Light regulation of stomatal conductance in intact leaves of this plant did occur, however, and was similar to light regulation observed in other species. The conductance of the green portion of the leaves was much greater in the light than in the dark, and was much greater than the conductance of the albino portion of the leaves. Stomata in the green portion of the leaves also showed greater opening in blue light than in red light. These results provide evidence that stomatal regulation in this variety of S. secundatum does not rely on photosystem II electron transport in guard cell chloroplasts.
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3283
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Thouless DJ, Li Q. Ring exchange and the fractional quantum Hall effect. PHYSICAL REVIEW. B, CONDENSED MATTER 1987; 36:4581-4583. [PMID: 9943469 DOI: 10.1103/physrevb.36.4581] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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3284
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Ko CM, Li Q, Wang R. Relativistic Vlasov equation for heavy-ion collisions. PHYSICAL REVIEW LETTERS 1987; 59:1084-1087. [PMID: 10035136 DOI: 10.1103/physrevlett.59.1084] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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3285
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Li Q, Altschuld RA, Stokes BT. Quantitation of intracellular free calcium in single adult cardiomyocytes by fura-2 fluorescence microscopy: calibration of fura-2 ratios. Biochem Biophys Res Commun 1987; 147:120-6. [PMID: 3115258 DOI: 10.1016/s0006-291x(87)80095-5] [Citation(s) in RCA: 89] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Isolated rat myocytes incubated with the acetoxy methyl ester of fura 2 contained partially hydrolyzed esters, necessitating in vivo calibration of the signals obtained by fluorescence microscopy for calculation of pCa. Ionophores did not produce reliable R'max and R'min values in respiring myocytes, and elevated free calcium caused individual cells to hypercontract and burst. These difficulties were overcome by superfusion with a glucose-free buffer containing an inhibitor and an uncoupler of oxidative phosphorylation. R'max and R'min values obtained by ionophore treatment of deenergized myocytes were normalized to an in vitro calibration curve. Resting pCa derived from the individual curves averaged 6.9 for calcium-tolerant rod-shaped myocytes.
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3286
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Lynn JW, Li WH, Li Q, Ku HC, Yang HD, Shelton RN. Magnetic fluctuations and two-dimensional ordering in ErBa2Cu. PHYSICAL REVIEW. B, CONDENSED MATTER 1987; 36:2374-2377. [PMID: 9943106 DOI: 10.1103/physrevb.36.2374] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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3287
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Cao ZA, Li Q, Shi Y, Zhong LC. [Kinetics of delta'-dehydrogenation of hydrocortisone by Arthrobacter simplex By-2-13. II. Kinetics of delta'-dehydrogenation of hydrocortisone by immobilized A. simplex By-2-13]. WEI SHENG WU XUE BAO = ACTA MICROBIOLOGICA SINICA 1987; 27:151-5. [PMID: 3630142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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3288
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Li Q, Lynn JW, Gotaas JA. Absolute measurement of the ordered magnetic moment in holmium-rich (Er1-xHox)Rh4B4. PHYSICAL REVIEW. B, CONDENSED MATTER 1987; 35:5008-5012. [PMID: 9940682 DOI: 10.1103/physrevb.35.5008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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3289
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Yin SN, Li Q, Liu Y, Tian F, Du C, Jin C. Occupational exposure to benzene in China. BRITISH JOURNAL OF INDUSTRIAL MEDICINE 1987; 44:192-5. [PMID: 3828244 PMCID: PMC1007803 DOI: 10.1136/oem.44.3.192] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Of a total of 528,729 workers exposed to benzene or benzene mixtures in China, 508,818 (96.23%) were examined. Altogether 2,676 cases of benzene poisoning were found, a prevalence of 0.15%. A higher prevalence of benzene poisoning was found in the cities of Hangjou, Hefei, Nanjing, Shenyang, and Xian. The geometric mean concentration of benzene in 50,255 workplaces was 18.1 mg/m3 but 64.6% of the workplaces had less than 40 mg/m3. There was a positive correlation between the prevalence of benzene poisoning and the concentration in shoemaking factories. The prevalence of benzene induced aplastic anaemia in shoemakers was about 5.8 times that occurring in the general population. The results of this investigation show the need for a practicable hygiene standard to prevent benzene poisoning.
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3290
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Zhong LC, Cao ZA, Li Q, Shi Y. [Kinetics of delta'-dehydrogenation of hydrocortisone by Arthrobacter simplex By-2-13. I. Kinetics of delta'-dehydrogenation of hydrocortisone by free cells of Arthrobacter simplex By-2-13]. WEI SHENG WU XUE BAO = ACTA MICROBIOLOGICA SINICA 1987; 27:45-51. [PMID: 3630138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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3291
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Li Q, Soukoulis CM. Half-flux-quantum magnetoresistance oscillations in disordered metal rings. PHYSICAL REVIEW LETTERS 1986; 57:3105-3108. [PMID: 10033955 DOI: 10.1103/physrevlett.57.3105] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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3292
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Li Q, Soukoulis CM. Quantum oscillations in one-dimensional metal rings: Average over disorder. PHYSICAL REVIEW. B, CONDENSED MATTER 1986; 33:7318-7321. [PMID: 9938081 DOI: 10.1103/physrevb.33.7318] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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3293
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Li Q. [On the formation of the surface zone on the enamel caries]. ZHONGHUA KOU QIANG KE ZA ZHI [CHINESE JOURNAL OF STOMATOLOGY] 1986; 21:90-2, 128. [PMID: 3463477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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3294
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Li Q, Powers PA, Smithies O. Nucleotide sequence of 16-kilobase pairs of DNA 5' to the human epsilon-globin gene. J Biol Chem 1985; 260:14901-10. [PMID: 4066658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
We have determined the nucleotide sequence of a 16-kilobase pair (kb) region of DNA on the 5' side of the human embryonic globin gene (epsilon). This sequence, when combined with previously published sequences, gives an uninterrupted sequence of 21 kb extending from approximately 19.5 kb upstream of the epsilon-globin gene to 0.3 kb 3' to its poly(A)-addition site. Computer-assisted analysis of this DNA reveals no large regions of self-homology but it shows the presence of seven members of the Alu family of repeated DNA, two very short members of the Kpn family of repeated DNA, one unusual direct repeat of 39 base pairs, and two potential stem and loop structures. The overall frequencies of mono- and dinucleotides within the 21 kb approximate those found in the total human genome but the distribution of (G + C)-rich regions signal many sequences of interest. The occurrences of some of the polynucleotides and polydinucleotides also differ appreciably from randomness, and the region contains several large stretches of these simple sequences. We found no evidence of strand asymmetry in the region. Homology between the nucleotide sequences of the human epsilon- and G gamma-globin genes extends only 100 base pairs 5' to the genes. One region, about 10 kb upstream of the gene, shows an apparent clustering of unusual sequence features. We discuss our sequence data in relation to the studies by others of DNAase hypersensitive sites and 5' transcription endpoints in this part of the beta-globin gene cluster.
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3295
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Li Q, Powers PA, Smithies O. Nucleotide sequence of 16-kilobase pairs of DNA 5' to the human epsilon-globin gene. J Biol Chem 1985. [DOI: 10.1016/s0021-9258(18)95678-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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3296
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Tuan D, Solomon W, Li Q, London IM. The "beta-like-globin" gene domain in human erythroid cells. Proc Natl Acad Sci U S A 1985; 82:6384-8. [PMID: 3879975 PMCID: PMC390720 DOI: 10.1073/pnas.82.19.6384] [Citation(s) in RCA: 520] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
We have mapped the distribution of the major and minor DNase I-hypersensitive sites in the human "beta-like-globin" gene domain. The minor DNase I-hypersensitive sites map close to the 5' end of each of the beta-like-globin genes. Their presence is specifically associated with the transcription of the immediate downstream beta-like-globin genes. The major DNase I-hypersensitive sites map in what appear to be the 5' and 3' boundary areas of the human beta-like-globin gene domain, a region estimated to span at least 90 kilobases of DNA. These major sites are present in various erythroid cells, which express predominantly either the embryonic, the fetal, or the adult beta-like-globin genes, and seem to be involved in defining the active beta-like-globin genes domain in cells of erythroid lineage. The four major DNase I-hypersensitive sites in the 5' boundary area, when correlated with sequencing data, are shown to be located in DNA regions containing enhancer core-like sequences and alternating purine and pyrimidine bases.
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3297
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Yang WL, Li Q. [Diagnosis and treatment of mammary tuberculosis]. ZHONGHUA WAI KE ZA ZHI [CHINESE JOURNAL OF SURGERY] 1985; 23:365-6, 383. [PMID: 4053854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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3298
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Li Q, Li H. Design of a broadband dichroic filter for transmitting visible and reflecting infrared bands. APPLIED OPTICS 1985; 24:1180. [PMID: 18217094 DOI: 10.1364/ao.24.001180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
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3299
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Li Q. [Bacterial colonization study of asymptomatic parturients and their neonates]. ZHONGHUA FU CHAN KE ZA ZHI 1985; 20:105-7, 127. [PMID: 3891247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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3300
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Wu GY, Wang LM, Zhang JW, Liang X, Zhou P, Li Q, Long GF, Tang ZN, Liang R, Fei YJ. [First-trimester fetal diagnosis of alpha-thalassemia]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 1984; 6:389-93. [PMID: 6242536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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