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Biomedical subjects

B Zhen

Publications and source records attributed to B Zhen.

At least 19 recordsLinked to original sources
PubMed2005

Concentration and detection of SARS coronavirus in sewage from Xiao Tang Shan Hospital and the 309th Hospital of the Chinese People's Liberation Army.

A worldwide outbreak of severe acute respiratory syndrome (SARS) had been reported. Over 8439 SARS cases and 812 SARS-related deaths were reported to the World Health Organization from 32 countries around the world up to 5 July 2003. The mechanism of transmission of SARS-CoV has been limited only to close contacts with patients. Attention was focused on possible transmission by the sewage system because laboratory studies showed that patients excreted coronavirus RNA in their stools in Amoy Gardens in Hong Kong. To explore whether the stool of SARS patients or the sewage containing the stool of patients would transmit SARS-CoV or not, we used a style of electropositive filter media particle to concentrate the SARS-CoV from the sewage of two hospitals receiving SARS patients in Beijing, as well as cell culture, semi-nested RT-PCR and sequencing of genes to detect and identify the viruses from sewage. There was no live SARS-CoV detected in the sewage in these assays. The nucleic acid of SARS-CoV was found in the sewage before disinfection from both hospitals by PCR. After disinfection, SARS-CoV RNA could be detected from some samples from the 309th Hospital of the Chinese People's Liberation Army, but not from Xiao Tang Shan Hospital after disinfection. In this study, we found that the virus can survive for 14 days in sewage at 4 degrees C, 2 days at 20 degrees C, and its RNA can be detected for 8 days though the virus had been inactivated. In conclusion, this study demonstrates that the RNA of SARS-CoV could be detected from the concentrates of sewage of both hospitals receiving SARS patients before disinfection and occasionally after disinfection though there was no live SARS-CoV; thus much attention should be paid to the treatment of stools of patients and the sewage of hospitals receiving SARS patients.

Bacteriophages↗
PubMed1999

Mobilization of peripheral blood stem cells with docetaxel and cyclophosphamide (CY) in patients with metastatic breast cancer: a randomized trial of 3 vs 4 g/m2 of CY.

The purpose of this study was to develop a regimen of docetaxel, cyclophosphamide (CY) and filgrastim for mobilization of peripheral blood stem cells (PBSC) in patients with metastatic breast cancer (n = 66). A phase I trial of CY 2, 3 or 4 g/m2 with docetaxel 100 mg/m2, in consecutive cohorts of four patients each, did not reveal any dose-limiting toxicities and subsequent patients were randomized to receive 3 or 4 g/m2 of CY. The median yield of CD34+ cells from all patients was 11.06x10(6)/kg (range, 0.03-84.77) from a median of two aphereses (range, 1-7); 6.52x10(6) CD34+ cells/kg/apheresis (range, 0.01-52.07). Target CD34+ cell doses > or =2.5 and > or =5.0x10(6)/kg were achieved in 89% and 79%, respectively. There were no statistically significant differences in CD34+ cell yields or target CD34+ cell doses achieved following 3 or 4 g/m2 of CY. Patients with only one prior chemotherapy regimen yielded a median of 12.82x10(6) CD34+ cells/kg/apheresis compared to 5.85 for those receiving > or =2 regimens (P = 0.03). It was concluded that the combination of docetaxel, 100 mg/m2, CY 3 g/m2 without mesna could be administered with acceptable toxicity with collection of adequate quantities of PBSC from the majority of patients.

Adult↗
PubMed1999

High-dose chemotherapy with peripheral blood stem cell support for stage IIIB inflammatory carcinoma of the breast.

The purpose of this study was to determine outcomes for 56 patients with inflammatory breast cancer (IBC) receiving high-dose chemotherapy (HDC) with cyclophosphamide, thiotepa and carboplatin (CTCb) with peripheral blood stem cell (PBSC) support. All patients received the same total amount of chemotherapy but there were differences in the sequence of therapy: 15 received induction chemotherapy, chemotherapy mobilization of PBSC and CTCb after surgery (adjuvant group) while 41 received induction chemotherapy with (n = 17) or without (n = 24) chemotherapy for mobilization of PBSC prior to surgery and CTCb after surgery (neoadjuvant group). Median time from diagnosis to HDC was 5.5 months (range 3.5-12.5). Fifty-one patients (91%) required admission to the hospital following HDC for a median of 11 days (range 5-25). There were two (4%) infectious deaths after HDC. Twenty-four patients (43%) have relapsed at a median of 18 months (range 8-50) from diagnosis resulting in death in 34%. The probabilities of overall (OS) and event-free survival (EFS) at 3 years for all 56 patients were 0.72 and 0.53, respectively, with a median follow-up of 44 months (range 15-76) from diagnosis. There were no differences in OS, EFS or patterns of relapse between patients in the adjuvant or neoadjuvant groups. These sequences of combined modality therapy incorporating HDC are comparable or superior to other intensive approaches for the treatment of IBC. Further improvements will be necessary to decrease systemic recurrences.

Adenocarcinoma↗
PubMed1999

Effect of CD34(+) cell dose on resource utilization in patients after high-dose chemotherapy with peripheral-blood stem-cell support.

PURPOSE: The mean time to neutrophil and platelet recovery for patients receiving high-dose chemotherapy (HDC) supported with peripheral-blood stem cells (PBSCs) is related to the dose of CD34(+) cells infused. The effect of cell dose on resource utilization after transplantation has not been previously reported. MATERIALS AND METHODS: We assessed CD34(+) cell dose and resource utilization for 1,317 patients undergoing transplantation with PBSCs from April 1991 to June 1997. PBSCs were collected after mobilization with chemotherapy and recombinant human granulocyte colony-stimulating factor (rhG-CSF). Daily measurement of the CD34(+) content of the PBSC collection was performed by a central laboratory using a single CD34(+) analysis technique. Resource utilization included engraftment parameters, length of stay, and transfusion requirements for 100 days posttransplantation. Analysis included descriptive statistics and multiple regression. RESULTS: Mean patient age was 47 years, and 86% of patients were female. Median cell dose was 3.6 x 10(6)/kg and 13.2 x 10(6)/kg for patients receiving less than 5.0 x 10(6) CD34(+) cells/kg and 5.0 x 10(6) or more CD34(+) cells/kg, respectively. Patients receiving less than 5. 0 x 10(6) CD34(+) cells/kg were more likely to have metastatic breast cancer or non-Hodgkin's lymphoma and required more platelet and RBC transfusions, 3.3 more hospital days, and increased antibiotic and antifungal use. In univariate analysis, the cost of care was $41,516 (+/-$20,876 SD) and $32,382 (+/-$16,353 SD) for patients with less than 5.0 x 10(6) CD34(+) cells/kg and 5.0 x 10(6) or more CD34(+) cells/kg, respectively. In multivariate analysis, patients with less than 5.0 x 10(6) CD34(+) cells/kg had an increase in costs of $5,062 (+/- $1,262 SE). CONCLUSION: Infusion of more than 5.0 x 10(6) CD34(+) cells/kg was associated with a reduction in resource utilization. Achieving a target of 5.0 x 10(6) CD34(+) cells/kg should have important clinical and economic benefits for patients.

Adolescent↗
PubMed1999

[Blood pressure examination using oscillometric method].

The effect of pressure sensor, filter and blood pressure algorithm upon oscillometric method is discussed in this paper. The design principle and parameters configuration used in portable blood pressure HOLTER are presented.

Algorithms↗
PubMed1998

Risk factors for injury among construction workers at Denver International Airport.

BACKGROUND: The Denver International Airport construction project provided a rare opportunity to identify risk factors for injury on a large construction project for which 769 contractors were hired to complete 2,843 construction contracts. Workers' compensation claims and payroll data for individual contracts were recorded in an administrative database developed by the project's Owner-Controlled Insurance Program. METHODS: From claims andy payroll data linked with employee demographic information, we calculated injury rates per 200,000 person-hours by contract and over contract characteristics of interest. We used Poisson regression models to examine contract-specific risk factors in relation to total injuries, lost-work-time (LWT), and non-LWT injuries. We included contract-specific expected loss rates (ELRs) in the model to control for prevailing risk of work and used logistic regression methods to determine the association between LWT and non-LWT injuries on contracts. RESULTS: Injury rates were highest during the first year of construction, at the beginning of contracts, and among older workers. Risk for total and non-LWT injuries was elevated for building construction contracts, contract for special trades companies (SIC 17), contracts with payrolls over $1 million, and those with overtime payrolls greater than 20%. Risk for LWT injuries only was increased for site development contracts and contract starting in the first year of construction. Contracts experiencing one or more minor injuries were four times as likely to have at least one major injury (OR = 4.0, 95% CI (2.9, 5.5)). CONCLUSIONS: Enhancement of DIA's safety infrastructure during the second year of construction appears to have been effective in reducing serious (LWT) injures. The absence of correlation between injury rates among contracts belonging to the same company suggest that targeting of safety resources at the level of the contract may be an effective approach to injury prevention. Interventions focused on high-risk contracts, including those with considerable overtime work, contracts held by special trades contractors (SIC 17), and contracts belonging to small and mid-sized companies, and on high-risk workers, such as those new to a construction site or new to a contract may reduce injury burden on large construction sites. The join occurrence of minor and major injuries on a contract level suggests that surveillance of minor injuries may be useful in identifying opportunities for prevention of major injures.

Accidents, Occupational↗
PubMed1998

High-dose chemotherapy with BUCY or BEAC and unpurged peripheral blood stem cell infusion in patients with low-grade non-Hodgkin's lymphoma.

Forty-nine patients with low-grade non-Hodgkin's lymphoma (NHL) received high-dose chemotherapy (HDC) with busulfan and cyclophosphamide (BUCY) or carmustine, etoposide, cytarabine and CY (BEAC) followed by unpurged autologous peripheral blood stem (PBSC) infusion. All patients had failed initial chemotherapy or progressed after an initial remission. Peripheral blood stem cells were mobilized with CY alone (n = 1), CY, etoposide (n = 19), or CY, etoposide and cisplatin (n = 29) followed by granulocyte colony-stimulating factor. Twenty-two patients received BU, 16 mg/kg, and CY, 120 mg/kg. Twenty-seven patients received carmustine 300 mg/m2, etoposide 600 mg/m2, cytarabine 600 mg/m2, and CY 140 mg/kg. Four patients (8%) died of non-relapse causes, two (9%) in the BUCY group and two (7%) in the BEAC group. Twenty-seven patients (55%) relapsed or progressed at a median of 9.4 months (2-38) from PBSC infusion. Ten patients who relapsed are alive a median of 31 months (range, 6-47) after relapse. The probabilities of relapse at 3.6 years for patients receiving BUCY or BEAC were 0.57 and 0.70, respectively (P = 0.92). Twenty-seven patients (55%) are alive at a median of 3.6 years (range, 1-5). The probabilities of survival at 3.6 years for patients receiving BUCY or BEAC were 0.58 and 0.55, respectively (P = 0.72). The probabilities of EFS at 3.6 years for patients receiving BUCY or BEAC were 0.36 and 0.28, respectively (P = 0.82). It was concluded that BUCY is an active regimen for the treatment of patients with low-grade NHL.

Adult↗
PubMed1998

High-dose chemotherapy in patients with breast cancer: evaluation of infusing peripheral blood stem cells containing occult tumor cells.

The purpose of this study was to evaluate the frequency of detecting occult tumor cells in peripheral blood stem cell (PBSC) harvests and to determine the impact of infusing such cells on relapses after high-dose chemotherapy (HDC). Peripheral blood stem cell harvests from 223 patients with breast cancer were examined by an immunocytochemistry (ICC) method for detection of occult tumor cells, and infused after HDC without consideration of test results. Two hundred and four patients, 114 with stage II-III and 90 with stage IV disease who received only PBSC, that were tested by ICC were evaluated for time to relapse. Five hundred and eighty-one of 619 PBSC harvests (94%) from 223 patients were tested. Fifty-three of 581 harvests (9%), 8% from stage II-III and 10% from stage IV patients, were positive by ICC (P = 0.68). Forty-one of 223 patients (18%), 17/122 (14%) with stage II-III and 24/101 (24%) with stage IV disease, had positive harvests (P = 0.06). Eleven percent of patients who had 1-2 harvests tested were positive as compared to 32% of patients who had > or =3 PBSC harvests tested (P < 0.001). Nineteen patients who were infused with a mixture of ICC negative and untested PBSC harvests were excluded from analyses of relapse. The probabilities of relapse at 18 months for the 97 patients with stage II-III disease infused with ICC-negative and the 17 with ICC-positive PBSC were 0.19 and 0.13, respectively (P = 0.48). The probabilities of relapse at 18 months for patients achieving a CR or a CR in non-bone sites and improvement in bone lesions were 0.55 for the ICC-negative group (n = 30) and 0.45 for the ICC-positive group (n = 11) (P = 0.60). It was concluded that occult tumor cells were detected by ICC in PBSC harvests from a relatively small fraction of women with breast cancer, but were not associated with a significant increase in the probability of early relapse or progression when infused after HDC.

Adult↗
PubMed1998

Phase I-II evaluation of rapid sequence tandem high-dose melphalan with peripheral blood stem cell support in patients with multiple myeloma.

This study was designed to determine the maximum tolerated dose (MTD) of high-dose melphalan (HDM), with peripheral blood stem cell support, that could be given twice within 90 days to patients with multiple myeloma. Twenty patients received tandem HDM at 160, 180 or 200 mg/m2 and a total of 55 were treated at the estimated MTD of 200 mg/m2. Seventeen of 55 (31%) did not receive cycle 2; six because of low CD34+ cell yields, three because of severe (n = 1) or fatal toxicities (n = 2) and eight for other reasons. The median interval between doses for 38 patients was 70 days (range 41-225). Three of 55 patients (5%) died of treatment-related causes. In patients completing two cycles of HDM, at any dose level, the complete remission rate improved from 15% following cycle 1 to 55% following cycle 2. The probabilities of survival, event-free survival and relapse or progression at 18 months for the 55 patients treated at the MTD were 0.84, 0.76 and 0.20, respectively, with a median follow-up of 19 months (range 9-36) from mobilization chemotherapy. It was concluded that two cycles of HDM, 200 mg/m2, could be administered to approximately 70% of patients under the age of 66 with multiple myeloma in a median interval of 70 days, with improvement in CR rates.

Adult↗
PubMed1998

Second attempts at mobilization of peripheral blood stem cells in patients with initial low CD34+ cell yields.

The purpose of this study was to determine the effectiveness of second mobilization strategies in patients who yielded < 2.5 x 10(6) CD34+ PBSC/kg after initial mobilization. Repeat mobilization attempts were made with chemotherapy and G-CSF (n = 61) or G-CSF alone (n = 58) in patients who failed initial mobilization with chemotherapy and G-CSF (n = 92) or G-CSF alone (n = 27). A median of 0.27 x 10(6) CD34+ cells/kg per apheresis was collected after the second mobilization, compared with 0.16 with initial harvests (p = 0.0001). Forty-eight percent achieved a target CD34+ cell dose > or = 2.5 x 10(6)/kg when harvests from the first and second mobilizations were combined. Fifteen of 17 patients (88%) with > or = 1.5 x 10(6) CD34+ cells/kg harvested after first mobilization had > or = 2.5 x 10(6) CD34+ cells/kg collected when first and second harvests were combined, as compared with 42 of 102 (41%) achieving < 1.5 x 10(6) CD34+ cells/kg with first PBSC harvests (p = 0.0001). Second mobilizations with chemotherapy and G-CSF or G-CSF alone resulted in similar CD34+ cell yields. Toxicities of second mobilizations were comparable with those of first mobilizations. Seventy-nine patients (66%) received high-dose chemotherapy with PBSC support, with recovery of neutrophils and platelets in a median of 11 and 15 days, respectively. Transplant-related mortality was 4%, and event-free survival at 2 years was 0.34. It was concluded that second mobilization attempts in patients who fail to achieve > or = 2.5 x 10(6) CD34+ cells/kg on initial mobilization were successful in 48% of patients. G-CSF alone was as effective as chemotherapy plus G-CSF in mobilizing CD34+ cells and was associated with less morbidity.

Adult↗
PubMed1998

A randomized trial of mobilization of peripheral blood stem cells with cyclophosphamide, etoposide, and granulocyte colony-stimulating factor with or without cisplatin in patients with malignant lymphoma receiving high-dose chemotherapy.

The purpose of this study was to evaluate the addition of cisplatin to cyclophosphamide, etoposide, and granulocyte colony-stimulating factor (G-CSF) for the mobilization of peripheral blood stem cells (PBSC). Eighty-one patients with malignant lymphoma were randomized to receive either cyclophosphamide 4 g/m2 and etoposide 600 mg/m2 (CE), and G-CSF 6 microg/kg/day (n = 41), or the same drugs with cisplatin 105 mg/m2 (CEP; n = 40) followed by collection of PBSC. Seventy-eight of 81 patients (96%) had apheresis performed and 70 (86%) received high-dose chemotherapy (HDC) with PBSC support. The median number of CD34+ cells collected after CE was 19.77 compared with 9.39 x 10(6)/kg after CEP (p = 0.09). More patients receiving CEP had grade 3-4 gastrointestinal (p = 0.03) and neurologic toxicities (p = 0.05), had significant delays in recovery of neutrophils (p = 0.0001) and platelets (p = 0.009), and received more red blood cell (p = 0.03) and platelet (p = 0.08) transfusions than patients receiving CE. There were no significant differences in treatment-related deaths, relapse, survival, or event-free survival between patients receiving CE or CEP when all 81 patients or the 70 patients receiving HDC were evaluated. It was concluded that the addition of cisplatin to CE did not improve CD34+ cell yields, was associated with more morbidity and resource utilization, and was not associated with improvement in outcomes.

Adult↗
PubMed1997

Interaction of genetic and exposure factors in the prevalence of berylliosis.

Prevalence of berylliosis, a lung disorder driven by the activation of beryllium-specific T cells, is associated with a major histocompatibility complex (MHC) class II marker (HLA-DPB1Glu69) and with the type of industrial exposure. We evaluated the interaction between marker and exposure in a beryllium-exposed population in which the prevalence of berylliosis was associated with machining beryllium. The presence of the marker was associated with higher prevalence (HLA-DPB1Glu69-positive machinists 25%; HLA-DPB1Glu69-negative machinists 3.2%, P = 0.05) and predicted berylliosis independent of machining history (odds ratios 11.8 and 10.1). The study shows that in berylliosis the carrier status of a genetic susceptibility factor adds to the effect of process-related risk factors.

Adult↗
PubMed1997

Engraftment and outcomes of patients receiving myeloablative therapy followed by autologous peripheral blood stem cells with a low CD34+ cell content.

Engraftment kinetics after high-dose chemotherapy (HDC) were evaluated in patients receiving autologous peripheral blood stem cell (PBSC) infusions with a low CD34+ cell content. Forty-eight patients were infused with < 2.5 x 10(6) CD34+ cells/kg; 36 because of poor harvests and 12 because they electively received only a fraction of their harvested cells. A median of 2.12 x 10(6) CD34+ cells/kg (range, 1.17-2.48) were infused following one of seven different HDC regimens. All patients achieved absolute neutrophil counts > or = 0.5 x 10(9)/l at a median of day 11 (range, 9-16). Forty-seven patients achieved platelet counts > or = 20 x 10(9)/l at a median of day 14 (range, 8-250). Nine of 47 (19%) had platelet recovery after day 21, 4/47 (9%) after day 100 and one died on day 240 without platelet recovery. Twenty-six patients (54%) died of progressive disease in 51-762 days; 22 (46%) are alive at a median of 450 days (range, 94-1844), 17 (35%) of whom are surviving disease-free at a median of 494 days (range, 55-1263). No patient died as a direct consequence of low blood cell counts. These data demonstrate that PBSC products containing 1.17-2.48 x 10(6) CD34+ cells/kg resulted in relatively prompt neutrophil recovery in all patients but approximately 10% had delayed platelet recovery.

Antigens, CD34↗
PubMed1997

High-dose chemotherapy and peripheral blood stem cell infusion in patients with non-Hodgkin's lymphoma: results of outpatient treatment in community cancer centers.

The outcomes for patients with non-Hodgkin's lymphoma (NHL) treated with high-dose chemotherapy (HDC) and peripheral blood stem cell (PBSC) infusion by practicing oncologists in community cancer centers in the United States were determined. Eighty-three patients with NHL, who had failed conventional chemotherapy, underwent mobilization of PBSC with chemotherapy and a recombinant growth factor in an outpatient facility. At a median of 40 days (range 26-119) after mobilization chemotherapy all received carmustine (300 mg/m2 x 1), etoposide (150 mg/m2 twice a day x 4 days), cytarabine (100 mg/m2 twice a day x 4 days) and cyclophosphamide (35 mg/kg x 4 days) (BEAC) followed by infusion of unmanipulated PBSC in an outpatient facility. The probabilities of treatment-related mortality, relapse/progression, overall survival (OS) and event-free survival (EFS) at 3 years for all 83 patients were 0.07, 0.57, 0.49 and 0.38, respectively. The probabilities of relapse/progression, OS and EFS at 3 years for 28 patients who had failed primary induction chemotherapy were 0.55, 0.42 and 0.38, respectively. The probabilities of OS and EFS for 27 patients in untreated first relapse were 0.52 and 0.44, respectively, as compared to 0.56 and 0.32, respectively, for 18 patients who had reinduction attempts prior to receiving mobilization chemotherapy (P = 0.81 for OS and 0.99 for EFS). No significant risk factors for the outcomes of TRM, relapse/progression, OS or EFS could be identified. These data demonstrate that approximately 40% of patients with NHL who have failed conventional chemotherapy become long-term disease-free survivors after mobilization chemotherapy, high-dose BEAC and PBSC infusion administered in an outpatient setting in community cancer centers, with the major cause of failure being relapse. Results obtained in this study are comparable to published data in similar patient populations receiving therapy as inpatients, suggesting that clinical trials involving well-tested HDC regimens can be carried out safely in this setting.

Adult↗
PubMed1997

A phase I-II study of high-dose melphalan, mitoxantrone and carboplatin with peripheral blood stem cell support in patients with advanced ovarian or breast carcinoma.

The purpose of this study was to develop a high-dose chemotherapy (HDC) and peripheral blood stem cell (PBSC) regimen for treatment of patients with ovarian carcinoma that could be administered in an outpatient setting. Fourteen patients with advanced ovarian (n = 9) or breast (n = 5) carcinoma, who had failed conventional chemotherapy, were entered into a dose-escalation trial to determine the maximum tolerated dose (MTD) of carboplatin that could be administered with fixed doses of melphalan (160 mg/m2) and mitoxantrone (50 mg/m2). Twenty-five additional patients were included in a phase II trial at the MTD. Two of two patients had grade 4 severe regimen-related toxicities (RRT), one fatal, at a dose level of 1600 mg/m2. Two of 29 patients (6.9%) treated at the MTD (carboplatin, 1400 mg/m2) died of RRT. All three patients who died of toxicity had a calculated AUC for carboplatin >30 mg/ml/min. Thirty-one patients with ovarian cancer who had failed chemotherapy were treated, 24 at the MTD. Fourteen of 20 patients (70%) with ovarian carcinoma with evaluable disease achieved a CR and seven (35%) are alive disease-free a median of 20 months (range, 7-26). Five of seven patients with ovarian cancer who had failed chemotherapy but were rendered clinically disease-free following surgery survive without progression a median of 13 months (range, 9-19). Eight of 16 (50%) platinum-resistant and 4/12 (33%) platinum-sensitive patients with ovarian cancer survive disease-free.

Adult↗
PubMed1997

Risks of beryllium disease related to work processes at a metal, alloy, and oxide production plant.

OBJECTIVES: To describe relative hazards in sectors of the beryllium industry, risk factors of beryllium disease and sensitisation related to work process were sought in a beryllium manufacturing plant producing pure metal, oxide, alloys, and ceramics. METHODS: All 646 active employees were interviewed; beryllium sensitisation was ascertained with the beryllium lymphocyte proliferation blood test on 627 employees; clinical evaluation and bronchoscopy were offered to people with abnormal test results; and industrial hygiene measurements related to work processes taken in 1984-93 were reviewed. RESULTS: 59 employees (9.4%) had abnormal blood tests, 47 of whom underwent bronchoscopy. 24 new cases of beryllium disease were identified, resulting in a beryllium disease prevalence of 4.6%, including five known cases (29/632). Employees who had worked in ceramics had the highest prevalence of beryllium disease (9.0%). Employees in the pebble plant (producing beryllium metal) who had been employed after 1983 also had increased risk, with a prevalence of beryllium disease of 6.4%, compared with 1.3% of other workers hired in the same period, and a prevalence of abnormal blood tests of 19.2%. Logistic regression modelling confirmed these two risk factors for beryllium disease related to work processes and the dependence on time of the risk at the pebble plant. The pebble plant was not associated with the highest gravimetric industrial hygiene measurements available since 1984. CONCLUSION: Further characterisation of exposures in beryllium metal production may be important to understanding how beryllium exposures confer high contemporary risk of beryllium disease.

Adult↗
PubMed1997

[Causes and influential factors of spectral broadening in Doppler flow signal].

Signals received are the resultant of the blood flow phasors in CW Doppler system and there are spectral broadening phenomena in it, in other words, frequency of signals corresponding to a moving RBC is not single. A model is presented that enables the detailed effects of spectral broadening to be calculated for a CW Doppler system by using geometric boundary argument. Results are given for the circular geometry.

Blood Flow Velocity↗