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S H Zhou

Publications and source records attributed to S H Zhou.

At least 19 recordsLinked to original sources
PubMed2002

Sigma-nucleus potential in A=28.

We have studied the (pi(-),K+) reaction on a silicon target to investigate the sigma-nucleus potential. The inclusive spectrum was measured at a beam momentum of 1.2 GeV/c with an energy resolution of 3.3 MeV (FWHM) by employing the superconducting kaon spectrometer system. The spectrum was compared with theoretical calculations within the framework of the distorted-wave impulse approximation, which demonstrates that a strongly repulsive sigma-nucleus potential with a nonzero size of the imaginary part reproduces the observed spectrum.

Journal Article↗
PubMed2002

Hypernuclear fine structure in (9)(lambda)Be.

With a germanium detector array (Hyperball), we observed two gamma-ray peaks corresponding to the two transitions (5/2(+)-->1/2(+) and 3/2(+)-->1/2(+)) in the (9)(Lambda)Be hypernucleus which was produced by the 9Be(K-,pi(-)) reaction. The energies of the gamma rays are 3029 +/- 2 +/- 1 keV and 3060 +/- 2 +/- 1 keV. The energy difference was measured to be 31.4(+2.5)(-3.6) keV, which indicates a very small Lambda-spin-dependent spin-orbit force between a Lambda and a nucleon. This is the smallest level splitting by far ever measured in a hypernucleus.

Journal Article↗
PubMed2001

[Clinical evaluation of intermittent strophanthin K therapy for congestive heart failure combined coronary artery disease].

OBJECTIVE: To evaluate the effects and safety of intermittent strophanthin K therapy (ISKT) for congestive heart failure combined coronary artery disease with sinus rhythm. METHODS: Two hundred patients divided into Group A (98 cases with maintenance digoxin therapy) and Group B (102 cases with ISKT). They were studied for 3 months and some of them for longer period. RESULTS: Comparing the pretreatment data: 1. heart rate (HR, bpm), 2. left ventricular ejection fraction (LVEF), 3. blood pressure (Bp, mmHg, calculated values as mean Bp for statistics). In group A, item 1. and 2. were significantly improved (item 1. 88 +/- 12 and 68 +/- 12, P < 0.01; item 2. 0.32 +/- 0.12 and 0.40 +/- 0.12, P < 0.01; item 3. showed no significant difference (126 +/- 21/90 +/- 6 and 128 +/- 21/80 +/- 5, P > 0.05). In group B, item 1., 2. and 3. were significantly improved (item 1. 90 +/- 10 and 70 +/- 11, item 2. 0.32 +/- 0.10 and 0.45 +/- 0.10, item 3. 128 +/- +/- 20/91 +/- 7 and 110 +/- 10/76 +/- 10, the p valves are the same < 0.01). As compared with the posttreatment data of both group A and B, HR, P > 0.05, there was no significant difference, LVEF, P < 0.05, there was significant difference, Bp, P < 0.01, there was significant difference. It showed no significant difference in total occurrence rate of digitalis overload or toxication between two groups also. CONCLUSION: ISKT for congestive heart failure combined coronary artery disease with sinus rhythm is effective and safe, with better improvement of heart function and Bp level.

Adult↗
PubMed2001

[Effect of low molecular weight heparin on unstable angina].

OBJECTIVE: To evaluate the effect of low molecular weight heparin (LMWH) and verus urokinase (UK) on unstable angina (UA). METHODS: Sixty seven patients with UA were divided in two groups by a single blind, controlled, randomized method: LMWH (anti-thrombi) group and UK (thromblytic therapy) group. Total ischemia load in 24 hours ambulatory ECG, mortality and cases of acute myocardial infarction (AMI) in 30 days were employed to compare the effect and safety between two groups. RESULTS: There was no significant difference in decreasing attacks of angina pectoris and total ischemia load between two groups. The UK group had two cases of AMI and five cases of complications of bleeding (two cases of epistaxis, two cases of bleeding gums, one case of hematochezia). CONCLUSION: Antithrombin therapy is prior to thromblitic therapy, treatment of LMWH is safer than that of low dose UK in UA.

Angina, Unstable↗
PubMed2001

[Effects of percutaneous transluminal coronary angioplasty and stenting on QT dispersion in patients with coronary heart disease].

OBJECTIVE: The aim of this study was to approach the effects of percutaneous transluminal coronary angioplasty (PTCA) and stenting on QT dispersion (QTd) in patients with coronary heart disease. METHODS: PTCA and stenting were performed successfully on 42 patients with coronary heart disease. QTd and corrected QTd (QTcd) were obtained with a standard 12-lead ECG before and after PTCA + Stent. RESULTS: QTd and QTcd after PTCA + Stent were reduced significantly compared to those before PTCA + Stent (P < 0.01). There were no significant difference in QTd and QTcd before PTCA + Stent between single vessel lesion and multi-vessel lesion, but after PTCA + Stent, QTd and QTcd in single vessel lesion were decreased significantly compared to those in multi-vessel lesion. The ventricular arrhythmia in 9 patients was over after PTCA + Stent. CONCLUSIONS: QTd and QTcd were decreased significantly after PTCA + Stent because of the improvement of myocardial ischemia and heterogeneous repolarization in patients with coronary heart disease. The degree in decreasing QTd and QTcd was associated with compensatory circulation in coronary artery.

Adolescent↗
PubMed2001

Measurement of the B(e2) of (7)(lambda)Li and shrinkage of the hypernuclear size.

We report on the first measurement of a hypernuclear gamma-transition probability. gamma rays emitted in the E2(5/2(+)-->1/2(+)) transition of (7)(Lambda)Li were detected by a large-acceptance germanium detector array (Hyperball), and the lifetime of the parent state ( 5/2(+)) was determined by the Doppler shift attenuation method. The obtained result, 5.8(+0.9)(-0.7)+/-0.7 ps, was then converted into the reduced transition probability [ B(E2)] to be B(E2;5/2(+)-->1/2(+)) = 3.6+/-0.5(+0.5)(-0.4) e(2) fm(4). Compared with the B(E2) of the corresponding E2(3(+)-->1(+)) transition in the 6Li nucleus, our result gives evidence that the size of the 6Li core in (7)(Lambda)Li is smaller than the 6Li nucleus in the free space.

Journal Article↗
PubMed2001

[Radiofrequency catheter abaltion of right atrioventricular accessory pathway by superior vena cava approach].

The radiofrequency ablation effect was observed in 21 patients with single right atrioventricular accessory pathway by superior vena cava approach. Because of many factors, radiofrequency ablation by routine inferior vena cava approach failed. However, all of these accessory pathways were successfully ablated by the superior vena cava approach with could significantly reduce operation and radiofrequency ablation time and exposed time in x-ray, and there were not any complications. The success was probably related to the good contact between the ablation catheter tip and ablation target point. It is suggested that radiofrequency ablation of right atrioventricular accessory pathways by superior vena cava approach is effective and safe when the routine inferior vena cava approach is difficult or unsuccessful.

Adolescent↗
PubMed2001

Using 12-lead ECG and synthesized VCG in detection of right ventricular hypertrophy with terminal right conduction delay versus partial right bundle branch block in the pediatric population.

In pediatric electrocardiogram (ECG) analysis, mild right ventricular hypertrophy (RVH) and especially mild RVH with terminal right conduction delay (RVHtcd) are often confused with partial right bundle branch block (PRBBB). This is problematic for computer ECG analysis algorithms and even for most experienced pediatric cardiologists. This study was designed to achieve better classification of mild RVHtcd and PRBBB by combining the 12-lead synthesized vectocardiogram (VCG) transverse plane measurements with scalar ECG measurements. Pediatric ECGs used in the study were recorded with 15 leads and a 500 Hz sampling rate at the Lucile Salter Packard Children's Hospital, Stanford University Medical Center. Out of 4,200 ECGs collected consecutively over a period of 18 months, 447 RVH, 335 RBBB and 589 Normal were interpreted by expert pediatric cardiologists, and were included in the study. Statistical comparison of ECG and VCG measurements were done in stratified ECG sets (412) that have a visually indistinguishable waveform pattern, 117 RVHtcd, 96 PRBBB and 199 normal, showed significant differences in initial and terminal vectors in the transverse plane. The mean angle of the initial vector was anterior (57.2 degrees +/- 41.8) in the normal group, left anterior in the PRBBB group (34.4 degrees +/- 39.5) and in the RVHtcd group (31.9 degrees +/- 41.0) and. The mean angle of the terminal vector was right anterior (158.3 degrees +/- 36.8) in the PRBBB group, rightward (179.7 degrees +/- 29.9) in the RVHtcd group and right posterior (212.6 degrees +/- 37.8) in the normal group. These are clearly applicable features for a classification algorithm. Significantly improved classification results were obtained from a new algorithm using combined ECG and VCG measurements versus an existing algorithm. The limitation of this study stems from the unavailability of a more reliable gold standard. It may be necessary to used body surface potentials obtained with a large number of electrodes to accurately differentiate the study groups.

Adolescent↗
PubMed2000

Observation of a spin-flip M1 transition in 7(lambda)Li.

Using a large-acceptance germanium detector array (Hyperball), we have observed a spin-flip M1 gamma transition between the ground-state spin doublet of (7)(Lambda)Li (3/2(+)-->1/2(+)). The observed energy of 691.7+/-0.6(stat)+/-1.0(syst) keV provides crucial information on the strength of the spin-spin interaction between a Lambda and a nucleon. This is the first observation of well-identified hypernuclear gamma transitions using germanium detectors.

Journal Article↗
PubMed2000

Geometrical dimensions of the lower lumbar vertebrae--analysis of data from digitised CT images.

The precise dimensions of the lumbar vertebrae and discs are critical for the production of appropriate spinal implants. Unfortunately, existing databases of vertebral and intervertebral dimensions are limited either in accuracy, study population or parameters recorded. The objective of this study is to provide a large and accurate database of lumbar spinal characteristics from 126 digitised computed tomographic (CT) images, reviewed using the Picture Archiving Communication System (PACS) coupled with its internal measuring instrumentation. These CT images were obtained from patients with low back pain attending the spinal clinic at the Hammersmith Hospitals NHS Trust. Measurements of various aspects of vertebral dimensions and geometry were recorded, including vertebral and intervertebral disc height. The results from this study indicated that the depth and width of the vertebral endplate increased from the third to the fifth lumbar vertebra. Anterior vertebral height remained the same from the third to the fifth vertebra, but the posterior vertebral height decreased. Mean disc height in the lower lumbar segments was 11.6 +/- 1.8 mm for the L3/4 disc, 11.3 +/- 2.1 mm for the L4/5, and 10.7 +/- 2.1 mm for the L5/S1 level. The average circumference of the lower endplate of the fourth lumbar vertebra was 141 mm and the average surface area was 1,492 mm2. An increasing pedicle width from a mean of 9.6 +/- 2.2 mm at L3 through to 16.2 +/- 2.8 mm at L5 was noted. A comprehensive database of vertebral and intervertebral dimensions was generated from 378 lumbar vertebrae from 126 patients measured with a precise digital technique. These results are invaluable in establishing an anthropometric model of the human lumbar spine, and provide useful data for anatomical research. In addition this is important information for the scientific planning of spinal surgery and for the design of spinal implants.

Adult↗
PubMed2000

False-negative and false-positive ECG diagnoses of Q wave myocardial infarction in the presence of right bundle-branch block.

Right bundle-branch block (RBBB) has not traditionally been seen as an obstacle to ECG diagnosis of Q wave myocardial infarction (MI)--in clinical electrocardiography and vectorcardiography--because this conduction disturbance is not believed to cause significant alterations in the spatial orientation of initial excitation wavefronts. In the era of large-scale clinical trials, however, where serial ECG analysis is among the major diagnostic tools in MI classification, both false-positive and false-negative diagnoses of MI in the presence of RBBB have become increasingly evident. Because of the limited detectability of Q wave MI by ECG in the presence of RBBB, the electrocardiographic finding of Q wave MI should not be regarded as an independent diagnostic tool. It is best to utilize independent corroboration to establish the diagnosis of transmural infarction when RBBB is present. Further investigations are warranted to better delineate sensitivity, specificity, and predictive value of Q wave MI in the presence of RBBB.

Atrial Function, Right↗
PubMed1999

Antigen-antibody complex as therapeutic vaccine for viral hepatitis B.

In a previous study, hepatitis B surface antigen (HBsAg) complexed to human anti-HBs immunoglobulins (HBIG) in excess of HBsAg was used as therapeutic vaccine to treat chronic hepatitis B patients and promising results were obtained. To study the mechanisms of this approach, mice were immunized with HBsAg or IC (immunogenic complex, i.e. HBsAg complexed with mouse polyclonal anti-HBs). Studies indicate that IC induced enhanced immune responses by increasing uptake of HBsAg through Fc receptors on antigen presenting cells and modulated HBsAg processing and presentation. This modulation led to stimulation of T cell responses, and increased production of IL-2 and IFN-gamma. Assay for antibody subclasses showed that higher ratio of IgG 2a was observed in the IC immunized group, which correlated with the production of lymphokine pattern. When alum was used as the adjuvant, though antibody response was enhanced, production of cytokines decreased. When DNA from a recombinant plasmid was added to IC as an adjuvant, the titer of anti-HBs was significantly higher than those in mice immunized only with the DNA or the IC. Since DNA immunization can induce both cellular and humoral immune responses, combined immunization using IC and DNA might serve as another type of therapeutic vaccine for viral hepatitis B.

Adjuvants, Immunologic↗
PubMed1999

Right bundle branch block as a cause of false-negative ECG classification of inferior myocardial infarction.

It is generally accepted in clinical electrocardiography that a right bundle branch block (RBBB) does not interfere with the electrocardiographic (ECG) diagnosis of myocardial infarction (MI). The basic assumption is that the initial excitation wavefronts are relatively unchanged in RBBB. This study compared serial changes in Q wave duration in inferior leads II, III, and aVF in 9 patients who developed RBBB within 3 weeks after myocardial revascularization procedure (RBBB group) and in 41 revascularized patients without RBBB in the same observation period (control group). Q wave durations in the electrocardiograms obtained before the patients' procedures were not significantly different between the study and control groups. However, Q wave durations shortened significantly more in the RBBB group than in the control group. The most pronounced Q wave duration shortening took place in lead aVF, -18.2 ms in the RBBB group versus -3.8 ms in the control group (P = .0001). The shortening was less pronounced, although significant, in leads II and III: II, -7.6 +/- -10.9 ms in the RBBB group vs -2.3 +/- -3.5 ms in the control group (P = .01); III, -11.3 +/- -10.5 ms vs -2.6 +/- -6.5 ms (P = .002); aVF, -18.2 +/- -13.5 ms vs -3.8 +/- -5.3 ms (P < .0001). It is concluded that incident RBBB complicating revascularization procedures may cause significant alterations in spatial orientation of the initial excitation wavefronts. This may be a potential source of false-negative ECG diagnosis of inferior MI, particularly in clinical trials where serial ECG analysis is an important part in MI classification.

Bundle-Branch Block↗
PubMed1997

Using automated analysis of the resting twelve-lead ECG to identify patients at risk of developing transient myocardial ischaemia--an application of an adaptive logic network.

The aim of this study was to introduce an adaptive logic network computing method for detecting patients who were likely to show transient ischaemic episodes during ambulatory Holter monitoring, using parameters from a previously recorded standard twelve-lead resting electrocardiogram (ECG). In the present study, the adaptive logic network computing method is compared with other commonly used classification methods, such as backpropagation network and discriminant analysis techniques. Of 1367 study subjects aged 65 and above, 733 were women and 634 were men. Ambulatory Holter recordings were made to detect episodic ischaemia in study patients. Those subjects showing ischaemic episodes were classified as 'ischaemic' patients, and the remaining subjects were 'non-ischaemic'. Accuracy was 67% using the adaptive logic network computing method, 56% using the backpropagation network computing method, and 65% using statistical discriminant analysis. We concluded that the adaptive logic network technique offers a slightly higher accuracy and shows several potential advantages for automated detection of ischaemia in resting electrocardiograms.

Adult↗
PubMed1996

Improved ECG models for left ventricular mass adjusted for body size, with specific algorithms for normal conduction, bundle branch blocks, and old myocardial infarction.

Considerable efforts have been invested recently to improve electrocardiographic (ECG) classification accuracy for left ventricular hypertrophy (LVH). This study examines how LVH classification accuracy is influenced by (1) the selection of an echocardiographic standard for LVH, (2) LVH severity level in the test groups, and (3) the adjustment of LVH criteria for obesity and age. Using data obtained from large, community-based populations, this study explores prospects for improving ECG models for LVH classification and examines some of the general characteristics of newer ECG models for estimating left ventricular mass (LVM) on a continuous scale. The results indicate that the apparent ECG classification accuracy for LVH is substantially influenced by echocardiographic standards and criteria for LVH, LVH severity level, and selection criteria for test populations, and these differences explain some of the often substantial differences in test results from clinical versus community-based evaluation studies. The low reproducibility of echocardiographic LVM as the standard is a limiting factor in attempts to improve ECG criteria for LVH and LVM prediction models. Adjustment of ECG amplitudes to anthropometric factors that simultaneously influence LVM may result in confounding effects and may lead to the development of inappropriate models. The performance of ECG models for LVM prediction improved substantially by the inclusion of body weight as a covariate with ECG variables. The addition of standing height and various covariates reflecting obesity did not improve LVM prediction accuracy. Compared to the older LVM prediction models of the Novacode ECG program, the correlation between echocardiographic and ECG estimates of LVM increased sufficiently (from 0.33 to 0.54 in women and from 0.46 to 0.62 in men) to suggest that these improved ECG models are suitable for monitoring LVH progression/ regression in study groups participating in hypertension intervention trials.

Adult↗
PubMed1996

Methodology of serial ECG classification using an adaptation of the NOVACODE for Q wave myocardial infarction in the Bypass Angioplasty Revascularization Investigation (BARI).

Serial electrocardiographic (ECG) changes are a critical component of the diagnostic algorithm for classification of myocardial ischemic events in large-scale clinical trials. This study describes a computerized serial ECG classification program developed at the St. Louis University Core ECG Laboratory for use in the Bypass Angioplasty Revascularization Investigation (BARI) trial, in which patients with multivessel coronary artery disease were randomized to receive either coronary artery bypass grafting or percutaneous transluminal coronary angioplasty. The St. Louis University program detects and codes serial changes in Q, ST, and T wave items according to Minnesota code (MC) criteria using a modified NOVACODE hierarchical classification system. Measurements using a seven-power calibrated coding loupe are used to generate the MC from a customized software program. Significant minor or major changes are detected by the serial comparison program and referred to a physician coder for verification. Serial comparison coding rules are used to adjust for weaknesses in the standard MC classification system resulting from instability at decision boundaries. Of 4,244 BARI randomized and registry study participants with follow-up ECGs received at the Core ECG Laboratory as of March 1995, a grade 2 MC Q wave progression was noted in 568 participants (13.4%) using MC criteria alone, as compared with 367 (8.6%) after the St. Louis University coding rules were applied. The incidence of grade 1 MC Q wave progressions was 16.4% (697/4,244) versus 6.1% (259/4,244) when the St. Louis University program was applied. Intraobserver variability for grade 2 Q wave progression codes determined from a sample of 812 serial.

Algorithms↗
PubMed1996

Utility of new electrocardiographic models for left ventricular mass in older adults. The Cardiovascular Health Study Collaborative Research Group.

Several multivariate statistical models have recently been introduced for estimation of left ventricular mass from standard 12-lead electrocardiographic measurements. The validity of these algorithms has not been adequately evaluated. The objective of this investigation was to compare the associations between echocardiographic and electrocardiographic left ventricular mass values with clinical and subclinical indexes of coronary heart disease. The evaluation was performed with participants of the Cardiovascular Health Study, a population-based sample of 5201 men and women aged 65 years and older. Echocardiographic M-mode measurements of left ventricular mass were performed from videotape recordings with the use of a strictly standardized protocol. Electrocardiographic algorithms of the Novacode program and new algorithms derived from the Cardiovascular Health Study population were used for left ventricular mass prediction. Echocardiographic and electrocardiographic determinations of left ventricular mass were technically successful in 3410 (65.6%) and 5013 (96.4%) participants, respectively. The Novacode model overestimated echocardiographic left ventricular mass. Compared with the Novacode model, the new Cardiovascular Health Study electrocardiographic model, which includes adjustment for body weight, eliminated left ventricular mass prediction bias and improved the correlation between echocardiographic and electrocardiographic left ventricular mass from .33 to .54 in women and from .46 to .51 in men. Echocardiographic and electrocardiographic models both demonstrated similar and about equally strong associations with overt and subclinical disease and with risk factors for left ventricular hypertrophy. These observations demonstrate the potential utility of electrocardiographic models for left ventricular mass estimation.

Age Factors↗