1
|
Deng LH, Wang ZP. [The prevalence of common complications among pneumoconiosis patients: a systematic review and Meta-analysis]. Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi 2023; 41:931-938. [PMID: 38195231 DOI: 10.3760/cma.j.cn121094-20230118-00018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2024]
Abstract
Objective: To analysis the main types and prevalences of complications among pneumoconiosis patients, and to provide scientific basis for the prevention and treatment of pneumoconiosis. Methods: In January 2023, literatures on pneumoconiosis complications published before December 31, 2022 in China National Knowledge Infrastructure (CNKI), Wanfang Database, Chinese Science & Technology Journal Database (VIP), PubMed and Web of Science were systematically searched. Literatures were selected according to inclusion and exclusion criteria, and relevant data were extracted. Quality assessment tool was used to evaluate the quality of the articles for this study. The combined prevalence of complications among pneumoconiosis patients was calculated by R 4.1.1 software. Subgroup analysis was carried out to explore the origin of heterogeneity. Results: Sixty-four eligible articles were selected from 2276 literatures related to pneumoconiosis and its complications. The combined prevalence of complications among pneumoconiosis patients was 21.1% (95% CI: 16.0%-26.3%, I(2)=99.9%). The combined prevalence of chronic obstructive pulmonary disease (COPD) was 26.4% (95%CI: 17.3%-35.6%, I(2)=97.1%), which was the highest among different types of complications among pneumoconiosis patients. Subgroup analyses revealed that the combined prevalence of tuberculosis among pneumoconiosis stage Ⅰ, Ⅱand Ⅲ were 13.8% (95%CI: 10.5%-17.2%, I(2)=99.6%), 18.4% (95% CI: 14.9%-22.0%, I(2)=99.3%) and 37.3% (95% CI: 30.7%-44.0%, I(2)=99.1%), respectively, showing a corresponding increasing tendency (P<0.05). The combined prevalence of tuberculosis among coal worker's pneumoconiosis patients was 12.9% (95% CI: 6.4%-19.3%, I(2)=97.9%), while the combined prevalence of tuberculosis among silicosis patients was 13.9% (95%CI: 10.0%-17.8%, I(2)=96.9%) . Conclusion: The prevalence of pneumoconiosis patients combined with different types of complications is high, and its prevalence increases with the severity of pneumoconiosis.
Collapse
Affiliation(s)
- L H Deng
- Journal of Preventive Medicine, Tianjin Center for Disease Control and Prevention, Tianjin 300011, China
| | - Z P Wang
- Department of Epidemiology and Biostatistics, Key Laboratory of Molecular Cancer Epidemiology, Tianjin, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin Medical University, Tianjin 300060, China Organ Transplantation Center, Tianjin First Central Hospital, Tianjin 300192, China
| |
Collapse
|
2
|
Xiang NB, Zhao XH, Deng LH, Li FY, Zheng S. Study on the relation of the solar coronal rotation with magnetic field structures. Sci Rep 2023; 13:21089. [PMID: 38036637 PMCID: PMC10689849 DOI: 10.1038/s41598-023-48447-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 11/27/2023] [Indexed: 12/02/2023] Open
Abstract
Daily solar spectral irradiances (SSIs) at the spectral intervals 1-40, 116-264 and 950-1600 nm and four categories of solar small-scale magnetic elements ([Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text]) are used to study the temporal variation of coronal rotation and investigate the relation of the coronal rotation with magnetic field structures through continuous wavelet transform and Pearson correlation analysis. The results reveal the contributions of different magnetic structures to the temporal variation of the rotation for the coronal atmosphere during different phases of the solar cycle. During the solar maximum, the temporal variation of rotation for the coronal plasma atmosphere is mainly dominated by the small-scale magnetic elements of [Formula: see text]; whereas during the epochs of the relatively weak solar activity, it is controlled by the joint effect of the small-scale magnetic elements of both [Formula: see text] and [Formula: see text]. The weaker the solar activity, the stronger the effect of [Formula: see text] would be. Furthermore, this study presents an explanation for the inconsistent results for the coronal rotation issue among the previous studies, and also reveals the reason why the coronal atmosphere rotates faster than the lower photosphere.
Collapse
Affiliation(s)
- N B Xiang
- Yunnan Observatories, Chinese Academy of Sciences, Kunming, 650011, China.
- State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing, 100190, China.
| | - X H Zhao
- State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing, 100190, China.
| | - L H Deng
- School of Mathematics and Computer Science, Yunnan Minzu University, Kunming, 650504, China.
| | - F Y Li
- State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing, 100190, China
- Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu, 610209, China
- Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University)-Ministry of Education, Nanjing, 210093, China
- The Key Laboratory on Adaptive Optics, Institute of Optics and Electronics, Chinese Academy of Sciences, Shuangliu, P.O. Box 350, Chengdu, 610209, Sichuan, China
| | - S Zheng
- College of Science, China Three Gorges University, Yichang, 443000, China
| |
Collapse
|
3
|
Deng LH, Geng JX, Xue Q, Jiang J, Chen LX, Wang JT. Correlation between nocturnal intermittent hypoxemia and mild cognitive impairment in the older adult and the role of BDNF Val66Met polymorphism: a hospital-based cross-sectional study. Sleep Breath 2023; 27:1945-1952. [PMID: 36567420 DOI: 10.1007/s11325-022-02772-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 11/14/2022] [Accepted: 12/16/2022] [Indexed: 12/27/2022]
Abstract
PURPOSE To explore the prevalence of nocturnal intermittent hypoxemia (NIH) in a tertiary hospital geriatric department and the relationship between NIH and mild cognitive impairment (MCI) in older adults, and to examine the role of brain-derived neurotrophic factor (BDNF) Val66Met polymorphism. METHODS Older adults aged ≥ 60 were enrolled. NIH and cognitive assessments were conducted. BDNF concentrations and BDNF Val66Met polymorphism were detected for a preliminary exploration of the possible mechanism of the process. RESULTS Of 325 older adults enrolled, 157 (48%) had NIH and were further divided into mild, moderate, and severe NIH groups according to their oxygen desaturation of ≥ 4% per hour of sleep (ODI4). MCI detection rate in the four groups gradually increased, and the differences were statistically significant (chi-square = 4.457, P = 0.035). ODI4 was negatively correlated with MoCA score in all participants (r = - 0.115, P = 0.039) and patients with NIH (r = - 0.199, P = 0.012). After adjusting for sex, age, and cardiovascular risk factors, NIH and MCI remained independently associated (OR = 3.13, 95% CI 1.03-9.53, P = 0.045). BDNF levels were positively correlated with MoCA score (r = 0.169, P = 0.028) and negatively correlated with nocturnal average oxygen saturation in patients with NIH (r = - 0.288, P = 0.008). Older adults with different BDNF Val66Met genotypes did not show significant differences in MCI rate and BDNF levels (P > 0.05). CONCLUSION The older adults with NIH have a higher MCI detection rate. BDNF levels may be a potential biomarker for cognitive dysfunction in patients with NIH.
Collapse
Affiliation(s)
- L H Deng
- Department of Geriatrics, Peking University People's Hospital, No. 11 Xizhimen South Street, Xicheng District, 100044, Beijing, People's Republic of China
| | - J X Geng
- Peking University Health Science Center, Beijing, China
| | - Q Xue
- Department of Geriatrics, Peking University People's Hospital, No. 11 Xizhimen South Street, Xicheng District, 100044, Beijing, People's Republic of China
| | - J Jiang
- Department of Geriatrics, Peking University People's Hospital, No. 11 Xizhimen South Street, Xicheng District, 100044, Beijing, People's Republic of China
| | - L X Chen
- Department of Geriatrics, Peking University People's Hospital, No. 11 Xizhimen South Street, Xicheng District, 100044, Beijing, People's Republic of China
| | - J T Wang
- Department of Geriatrics, Peking University People's Hospital, No. 11 Xizhimen South Street, Xicheng District, 100044, Beijing, People's Republic of China.
| |
Collapse
|
4
|
Zeng Q, Deng LH, Li XL, Gao Y, Liu J, Yang XY, Tang HJ, Wang X. [Epidemiological characteristics of new pneumoconiosis in different industries in Tianjin]. Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi 2021; 39:118-122. [PMID: 33691366 DOI: 10.3760/cma.j.cn121094-20200413-00187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To analyze the distribution characteristics of new pneumoconiosis in different industries in Tianjin from 2009 to 2018, in order to provide a theoretical basis for the prevention and treatment of pneumoconiosis. Methods: In November 2019, the data of new pneumoconiosis cases in Tianjin from 2009 to 2018 were collected and classified according to difference industries. The epidemiological characteristics of new pneumoconiosis in different industries were analyzed based on time, type of pneumoconiosis, type of work, age, and working age. Results: A total of 4657 new cases of pneumoconiosis were reported in Tianjin from 2009 to 2018, 4640 cases (99.63%) in the first stage, 13 cases (0.28%) in the second stage, and 4 case (0.09%) in the third stage. The number of new cases increased with time and then decreased. Among them, there were 3482 males (74.77%) and 1175 females (25.23%) . The proportion of women with new pneumoconiosis in the non-metallic mineral products industry was the highest, and the differences were statistically significant (P<0.05) . There are differences in the distribution of new pneumoconiosis species in different industries (χ(2)=4920.11, P<0.05) . Silicosis is mainly distributed in non-metallic mineral products industry, metal smelting and rolling processing industry, petroleum processing coking and nuclear fuel processing industries. Foundry worker's pneumoconiosis is mainly distributed in the general equipment manufacturing industry and special equipment manufacturing industry, and cement pneumoconiosis is mainly distributed in the non-metallic mineral products industry. The types of work are mainly distributed in smelting, casting, raw materials and forming workers, and the sum of the three accounts for 36.46% (1689/4657) . The M (P(25), P(75)) of diagnosis age was 56.0 (50.0, 63.0) years, and the M (P(25), P(75)) of working age was 19.0 (16.0, 26.0) years. The working age of new pneumoconiosis patients in the petroleum processing, coking and nuclear fuel processing industries is 19.0 (16.0, 26.0) years, which is shorter than that of other industries (P<0.05) ; The diagnostic age of the general equipment manufacturing industry is 54.0 (49.0, 59.0) years, which is less than that of other industries (P<0.05) . New pneumoconiosis is mainly distributed in large and medium-sized enterprises. New cases of pneumoconiosis in non-metallic mineral products industry, metal smelting, calendar processing industry and general equipment manufacturing industry are mainly distributed in large and medium-sized enterprises. New cases of pneumoconiosis in the metal products industry, special equipment manufacturing industry and petroleum processing, coking and nuclear fuel processing industries are mainly distributed in large enterprises. Conclusion: The work of preventing and controlling pneumoconiosis in Tianjin has a long way to go. We should implement targeted measures according to the characteristics of pneumoconiosis industry, strengthen the supervision of hazard industries, and effectively control the occurrence of pneumoconiosis.
Collapse
Affiliation(s)
- Q Zeng
- Tianjin Centers for Disease Control and Prevention, Tianjin 300011, China
| | - L H Deng
- Tianjin Centers for Disease Control and Prevention, Tianjin 300011, China
| | - X L Li
- Tianjin Centers for Disease Control and Prevention, Tianjin 300011, China
| | - Y Gao
- Tianjin Centers for Disease Control and Prevention, Tianjin 300011, China
| | - J Liu
- Tianjin Centers for Disease Control and Prevention, Tianjin 300011, China
| | - X Y Yang
- Tianjin Centers for Disease Control and Prevention, Tianjin 300011, China
| | - H J Tang
- Tianjin Centers for Disease Control and Prevention, Tianjin 300011, China
| | - X Wang
- Tianjin Centers for Disease Control and Prevention, Tianjin 300011, China
| |
Collapse
|
5
|
Wang ZX, Huang CY, Hua YP, Huang WQ, Deng LH, Liu KX. Dexmedetomidine reduces intestinal and hepatic injury after hepatectomy with inflow occlusion under general anaesthesia: a randomized controlled trial. Br J Anaesth 2014; 112:1055-64. [PMID: 24771805 DOI: 10.1093/bja/aeu132] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND We compared intestinal, hepatic, and other organ function after hepatic portal occlusion with or without dexmedetomidine administration under general anaesthesia. METHODS In this prospective, randomized double-blind investigation, 44 patients undergoing elective hepatectomy with inflow occlusion were randomized into a dexmedetomidine group or a control group. The dexmedetomidine group received an initial dexmedetomidine loading dose of 1 μg kg(-1) over 10 min followed by a maintenance dose of 0.3 μg kg(-1) h(-1). In the control group, 0.9% sodium chloride was administered. The primary outcome was serum diamine oxidase (DAO) activity reflecting intestinal injury. The secondary outcomes included variables reflecting intestinal, hepatic, kidney, and cardiopulmonary function, and biomarkers of oxidative stress and systemic inflammatory response. RESULTS DAO activity was lower in the dexmedetomidine group than in the control group at 6 and 24 h after liver reperfusion [9.77 (1.07) vs14.29 (1.43) units ml(-1), P=0.021; 9.67 (0.98) vs 13.97 (1.31) units ml(-1), P=0.017]. d-lactate acid levels were lower during 1-72 h after liver reperfusion compared with the control group (all P<0.05). Also, the intestinal injury severity grade was decreased by dexmedetomidine (P=0.038). The biomarkers reflecting liver injury increased over time, but were lower in the dexmedetomidine group (all P<0.05), while the variables reflecting cardiopulmonary and renal function showed no differences between the groups (all P>0.05). CONCLUSIONS Dexmedetomidine administered perioperatively attenuates intestinal and hepatic injury in patients undergoing elective liver resection with inflow occlusion without any potential risk. CLINICAL TRIAL REGISTRATION ChiCTR-TRC-11001530, September 2011.
Collapse
Affiliation(s)
- Z X Wang
- Department of Anaesthesiology, The First Affiliated Hospital, Sun Yat-Sen University, No. 58, Zhongshan II Road, Guangzhou 510080, China
| | - C Y Huang
- Department of Anaesthesiology, The First Affiliated Hospital, Sun Yat-Sen University, No. 58, Zhongshan II Road, Guangzhou 510080, China
| | - Y P Hua
- Department of Hepatobiliary Surgery, The First Affiliated Hospital, Sun Yat-Sen University, No. 58, Zhongshan II Road, Guangzhou 510080, China
| | - W Q Huang
- Department of Anaesthesiology, The First Affiliated Hospital, Sun Yat-Sen University, No. 58, Zhongshan II Road, Guangzhou 510080, China
| | - L H Deng
- Department of Laboratory Medicine, The First Affiliated Hospital, Sun Yat-Sen University, No. 58, Zhongshan II Road, Guangzhou 510080, China
| | - K X Liu
- Department of Anaesthesiology, The First Affiliated Hospital, Sun Yat-Sen University, No. 58, Zhongshan II Road, Guangzhou 510080, China
| |
Collapse
|
6
|
Sham JS, Crenshaw BR, Deng LH, Shimoda LA, Sylvester JT. Effects of hypoxia in porcine pulmonary arterial myocytes: roles of K(V) channel and endothelin-1. Am J Physiol Lung Cell Mol Physiol 2000; 279:L262-72. [PMID: 10926549 DOI: 10.1152/ajplung.2000.279.2.l262] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Effects of acute hypoxia on intracellular Ca(2+) concentration ([Ca(2+)](i)) and cell length were recorded simultaneously in proximal and distal pulmonary (PASMCs) and femoral (FASMCs) arterial smooth muscle cells. Reducing PO(2) from normoxia to severe hypoxia (PO(2) < 10 mmHg) caused small but significant decreases in length and a reversible increase in [Ca(2+)](i) in distal PASMCs and a small decrease in length in proximal PASMCs but had no effect in FASMCs, even though all three cell types contracted significantly to vasoactive agonists. Inhibition of voltage-dependent K(+) (K(V)) channel with 4-aminopyridine produced a greater increase in [Ca(2+)](i) in distal than in proximal PASMCs. In distal PASMCs, severe hypoxia caused a slight inhibition of K(V) currents; however, it elicited further contraction in the presence of 4-aminopyridine. Endothelin-1 (10(-10) M), which itself did not alter cell length or [Ca(2+)](i), significantly potentiated the hypoxic contraction. These results suggest that hypoxia only has small direct effects on porcine PASMCs. These effects cannot be fully explained by inhibition of K(V) channels and were greatly enhanced via synergistic interactions with the endothelium-derived factor endothelin-1.
Collapse
Affiliation(s)
- J S Sham
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, The Johns Hopkins Medical Institutions, Baltimore, Maryland 21224, USA.
| | | | | | | | | |
Collapse
|
7
|
Sham JS, Song LS, Chen Y, Deng LH, Stern MD, Lakatta EG, Cheng H. Termination of Ca2+ release by a local inactivation of ryanodine receptors in cardiac myocytes. Proc Natl Acad Sci U S A 1998; 95:15096-101. [PMID: 9844021 PMCID: PMC24581 DOI: 10.1073/pnas.95.25.15096] [Citation(s) in RCA: 134] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In heart, a robust regulatory mechanism is required to counteract the regenerative Ca2+-induced Ca2+ release from the sarcoplasmic reticulum. Several mechanisms, including inactivation, adaptation, and stochastic closing of ryanodine receptors (RyRs) have been proposed, but no conclusive evidence has yet been provided. We probed the termination process of Ca2+ release by using a technique of imaging local Ca2+ release, or "Ca2+ spikes", at subcellular sites; and we tracked the kinetics of Ca2+ release triggered by L-type Ca2+ channels. At 0 mV, Ca2+ release occurred and terminated within 40 ms after the onset of clamp pulses (0 mV). Increasing the open-duration and promoting the reopenings of Ca2+ channels with the Ca2+ channel agonist, FPL64176, did not prolong or trigger secondary Ca2+ spikes, even though two-thirds of the sarcoplasmic reticulum Ca2+ remained available for release. Latency of Ca2+ spikes coincided with the first openings but not with the reopenings of L-type Ca2+ channels. After an initial maximal release, even a multi-fold increase in unitary Ca2+ current induced by a hyperpolarization to -120 mV failed to trigger additional release, indicating absolute refractoriness of RyRs. When the release was submaximal (e.g., at +30 mV), tail currents did activate additional Ca2+ spikes; confocal images revealed that they originated from RyRs unfired during depolarization. These results indicate that Ca2+ release is terminated primarily by a highly localized, use-dependent inactivation of RyRs but not by the stochastic closing or adaptation of RyRs in intact ventricular myocytes.
Collapse
Affiliation(s)
- J S Sham
- Division of Pulmonary and Critical Care Medicine, The Johns Hopkins Medical Institutions, Baltimore, MD 21224, USA.
| | | | | | | | | | | | | |
Collapse
|
8
|
Deng LH, Barbenel JC, Lowe GD. Influence of hematocrit on erythrocyte aggregation kinetics for suspensions of red blood cells in autologous plasma. Biorheology 1994; 31:193-205. [PMID: 8729481 DOI: 10.3233/bir-1994-31207] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The influence of hematocrit on red blood cell aggregation was investigated using a modified automated Myrenne Aggregometer System. Hematocrit values ranged from 20-70% at 10% increments, and were produced by resuspending washed red cells in autologous plasma. The Myrenne System produced seven kinetic parameters of red cell aggregation. The results indicate that hematocrit (Hct) had a strong and nonlinear effect on erythrocyte aggregability. At both low and high hematocrit, the aggregation intensity (AI) tends to decrease, reaching a plateau at 40% hematocrit. The disaggregation shear rate demonstrates an exponential relationship as In gamma TMIN = 3.29-0.0837 Hct. Time constants of the aggregation process such as T1/2, TSLOW and TFAST were rather inconsistent. The increase of hematocrit increased the rate of the fast phase aggregation and slightly slowed the secondary aggregation.
Collapse
Affiliation(s)
- L H Deng
- Bioengineering Unit, University of Strathclyde, Glasgow, UK
| | | | | |
Collapse
|
9
|
Deng LH, Yu JR, Xie GL. [Study of the autologous mixed lymphocyte reaction in patients with chronic ITP]. Zhonghua Nei Ke Za Zhi 1993; 32:88-90. [PMID: 8404331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Autologous mixed lymphocyte reaction (AMLR) was studied in 37 patients with chronic ITP (including 27 active cases and 10 inactive cases) and 37 sex and age group matched healthy controls. AMLR was markedly decreased in all the patients of both active and inactive groups (P < 0.05). T cells and non-T cells from the peripheral blood of 10 patients with ITP and 10 Sex and age group matched healthy controls were investigated for HLA-DR expression by direct immunofluorescence. The percentage of DR+ non-T cells was significantly decreased in Patients with ITP as compared with the controls (P < 0.01) and there was a positive between AMLR and platelet counts (r = 0.92, P < 0.01; r = 0.75, P < 0.05 respectively). In addition, the percentage of DR+T cells was significantly increased in patients with ITP in comparison with the controls (P < 0.01). There was an inverse correlation between the percentage of DR+T cells and platelet counts (r = -0.82, P < 0.01) as well as AMLR (r = -0.81, P < 0.01). This study suggested that these were defects of the immunoregulatory function in patients with ITP as manifested by decreased AMLR, which might be related to the abnormal expression of surface DR+ antigen on non-T cells.
Collapse
Affiliation(s)
- L H Deng
- Department of hematology, First school of clinical Medicine, Beijing Medical University
| | | | | |
Collapse
|
10
|
Abstract
We measured the Fahraeus effect of blood flowing in a sheet flow model formed with two glass slides. The number of red blood cells in the sheet flow was counted to determine a sheet hematocrit Hs and the discharge hematocrit Hd was measured from blood collection. For a Hd in the range of 3 to 30 percent, we find that Hs/Hd is about .83 for a gap of 4.1 microns. When the discharge hematocrit is 30 percent, the ratio decreases to .66 as the gap approaches 7 microns and then increases as the gap becomes thicker. The results indicate that the hematocrit ratio for a gap thicker than 4.1 microns is an increasing function of the discharge hematocrit. The value of Hs/Hd found for the sheet flow models and its dependence on Hd are comparable to those of circular tubes when their diameter equals the gap thickness.
Collapse
Affiliation(s)
- L H Deng
- Biomechanics Institute, Chongqing University, Sichuan, China
| | | | | | | | | |
Collapse
|