Objective To investigate the impact of variations in volute cross-sectional area on the flow characteristics and hemolytic performance of centrifugal blood pumps by designing six volute structures.Methods Computational fluid dynamics and the Lagrangian method were used to analyze flow characteristics and predict hemolysis in blood pumps with different volute designs.Results The annular volute pump showed the poorest hydraulic performance,while the hydraulic performance of the S-shaped volute was the best,which was improved by 35.29％compared to that of the annular volute.Some volutes experienced stagnation zones at the helical inlet(0°-90°)and significant backflow at the outlet(270°-360°).The downward concave-shaped volute had the highest hemolysis index(HI),i.e.,9.59×10-4.Meanwhile,the HI of the annular volute was the lowest,which was 71.85％less than the concave-shaped volute.Conclusions Reducing the gradient of the area variation at the helical inlet and outlet can prevent flow stagnation and backflow.A higher HI arises due to the prolonged exposure of red blood cells to high shear stress.This study provides a theoretical basis for designing and optimizing volute structures of centrifugal blood pumps.

Tesla blood pumps demonstrate a reduced propensity for hemolysis and thrombosis compared with vane blood pumps. Considering the restricted driving force within the secondary flow channel of vane blood pumps, along with the low hydraulic efficiency of conventional Tesla blood pumps and their internal flow characteristics that significantly contribute to hemolysis and thrombosis, this study introduces a set of vanes atop the rotor of the Tesla blood pump. This forms a dual-fluid domain rotor, and an axial dual-outlet volute shell structure is adopted to realize the separation of the fluid domains. Through numerical simulations of the new structure, a comparative analysis was conducted in this study on the internal flow characteristics of double-outlet and single-outlet volute shells, and symmetric and asymmetric cross-sections of the same rotor. The results indicate that the flow field distribution is more uniform under the double-outlet volute shell structure, and overall energy dissipation is decreased. After implementing the double-outlet design, in the asymmetric cross-section, compared with the symmetric cross-section, the fluid velocity gradient and turbulent kinetic energy at the tongue of the septum are reduced, and the fluid velocity gradient at the convergence of the diffuser tube outlets are also decreased. The maximum scalar stress is lower, and the decline in head and efficiency is mitigated. Moreover, compared with the single-outlet volute shell, the hemolysis index in the asymmetric cross-section is reduced. In summary, this paper proposes a novel dual-outlet centrifugal disk blood pumps, which can provide a reference for the structural design and performance optimization of magnetically levitated centrifugal blood pumps.
Heart-Assist Devices ; Humans ; Equipment Design ; Hemolysis ; Computer Simulation

Objective To study the effects of different clearance conditions(equal upper and lower axial clearance,change of upper/lower axial clearance,axial displacement of blades)on efficiency and hemolysis performance of blood pump.Methods The blood pumps under three kinds of clearance conditions were numerically simulated by computational fluid dynamics.Results For efficiency,when the upper and lower axial clearance was equal,the lower axial clearance was unchanged and the upper axial clearance was reduced,the efficiency of blood pump could be improved by 0.85%,1.71%and 2.90%,respectively.While the upper shaft clearance remained unchanged,the lower shaft clearance was decreased by 1.18%.For hemolysis,the increase of the clearance could reduce the hemolysis index(HI)under the first two clearance conditions,while the axial migration of the blade wheel would increase the HI.When the upper axial clearance was unchanged and the lower axial clearance was 0.3 mm,the HI was the largest,which was 8.65×10-4.When the upper and lower axial clearance was 0.7 mm,the HI was the smallest,which was 4.51×10-4.Conclusions Improving blood pump clearance is helpful to optimize the performance of blood pump.This study can provide some references for the design and optimization of interstitial structure of blood pump.

Objective To investigate the impact of variations in volute cross-sectional area on the flow characteristics and hemolytic performance of centrifugal blood pumps by designing six volute structures.Methods Computational fluid dynamics and the Lagrangian method were used to analyze flow characteristics and predict hemolysis in blood pumps with different volute designs.Results The annular volute pump showed the poorest hydraulic performance,while the hydraulic performance of the S-shaped volute was the best,which was improved by 35.29％compared to that of the annular volute.Some volutes experienced stagnation zones at the helical inlet(0°-90°)and significant backflow at the outlet(270°-360°).The downward concave-shaped volute had the highest hemolysis index(HI),i.e.,9.59×10-4.Meanwhile,the HI of the annular volute was the lowest,which was 71.85％less than the concave-shaped volute.Conclusions Reducing the gradient of the area variation at the helical inlet and outlet can prevent flow stagnation and backflow.A higher HI arises due to the prolonged exposure of red blood cells to high shear stress.This study provides a theoretical basis for designing and optimizing volute structures of centrifugal blood pumps.

Objective To study the effects of different clearance conditions(equal upper and lower axial clearance,change of upper/lower axial clearance,axial displacement of blades)on efficiency and hemolysis performance of blood pump.Methods The blood pumps under three kinds of clearance conditions were numerically simulated by computational fluid dynamics.Results For efficiency,when the upper and lower axial clearance was equal,the lower axial clearance was unchanged and the upper axial clearance was reduced,the efficiency of blood pump could be improved by 0.85%,1.71%and 2.90%,respectively.While the upper shaft clearance remained unchanged,the lower shaft clearance was decreased by 1.18%.For hemolysis,the increase of the clearance could reduce the hemolysis index(HI)under the first two clearance conditions,while the axial migration of the blade wheel would increase the HI.When the upper axial clearance was unchanged and the lower axial clearance was 0.3 mm,the HI was the largest,which was 8.65×10-4.When the upper and lower axial clearance was 0.7 mm,the HI was the smallest,which was 4.51×10-4.Conclusions Improving blood pump clearance is helpful to optimize the performance of blood pump.This study can provide some references for the design and optimization of interstitial structure of blood pump.

Objective:To study the clinical characteristics of patients with brucella bloodstream infection in different age groups, and provide a basis for clinicians to take targeted diagnosis and treatment measures. Methods:Demographic data and general condition (age, sex, occupation, location, onset season, source of infection, clinical stage), clinical characteristics (main clinical symptoms and complications), and laboratory test results (routine and pathogenic tests) of adult patients with brucella bloodstream infection admitted to the Affiliated Hospital of Chengde Medical College from January 2015 to January 2020 were collected. According to the age stratification standards recommended by the World Health Organization, the patients were divided into a young group (18 - 44 years old), a middle-aged group (45 - 59 years old), and an elderly group (≥60 years old), and various indicators among different age groups were compared and analyzed. Results:A total of 75 patients were included, including 15 cases (20.00%) in the young group, 37 cases (49.33%) in the middle-aged group, and 23 cases (30.67%) in the elderly group. Among them, 61 cases (81.33%) were males and 14 cases (18.67%) were females, with statistically significant differences in gender ratios among different age groups (χ 2 = 7.28, P = 0.021). The majority of patients were farmers (64 cases, 85.33%), and 92.00% (69/75) of the patients came from rural areas. The main sources of infection were infected cattle and sheep, and contaminated food (39 cases, 52.00%). The main season of onset was spring and summer (45 cases, 60.00%). The clinical staging was mainly in the acute phase (66 cases, 88.00%). In terms of clinical symptoms, the young group of patients had no symptoms of low back pain, while the incidence rates of low back pain in the middle-aged and elderly groups were 35.14% (13/37) and 30.43% (7/23), respectively. There was a statistically significant difference between the three groups (χ 2 = 6.98, P = 0.031). In terms of complications, there were no cases of concurrent spondylitis in the young group of patients. The incidence rates of spondylitis in the middle-aged and elderly groups were 32.43% (12/37) and 34.78% (8/23), respectively. There was a statistically significant difference among the three groups (χ 2 = 6.86, P = 0.032). In terms of routine laboratory examinations, there were statistically significant differences in the proportion of blood lymphocytes and albumin levels among patients of different age groups ( F = 3.41, 3.27, P = 0.038, 0.044). In terms of pathogenic examination, there was a statistically significant difference in the median alarm time for positive blood culture among patients of different age groups ( H = 9.54, P = 0.008), with the middle-aged group having the longest (66.24 h) and the elderly group having the shortest (58.80 h). Conclusions:The clinical characteristics of patients with brucella bloodstream infection vary among different age groups, middle-aged and elderly patients are prone to low back pain symptoms, accompanied by spondylitis. Clinicians should pay attention to the patient's own characteristics and provide targeted diagnosis and treatment.

Objective To investigate and predict the molecular targets and mechanism of Huanglian Jiedu Decoction (黄连解毒汤, HLJDD) in the treatment of Corona Virus Disease 2019 (COVID-19) through network pharmacology and molecular docking analysis. Methods The chemical constituents and action targets of HLJDD were retrieved on Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP), SymMap v2, Encyclopedia of Traditional Chinese Medicine (ETCM), a High-throughput Experiment- and Reference-guided Database of Traditional Chinese Medicine (HERB), and Traditional Chinese Medicine Integrated Database (TCMID). UniProt and GeneCards were used to query the target genes that corresponding to the active compounds, and then a compound-target network was constructed using Cytoscape 3.7.2. Gene Ontology (GO) database was used to annotate GO functions. Kyoto Encyclopedia of Genes and Genomes (KEGG) was used to predict the possible mechanisms of active compounds. The Database for Annotation, Visualization and Integrated Discovery (DAVID) was used to analysis the tissue enrichment. The main active compounds in HLJDD are molecularly docked with their corresponding related targets. Results Seventy-six compounds were screened and 458 corresponding targets in the network were obtained. Gene annotation showed that the targets were involved mainly in 1 953 biological processes. 884 signaling pathways was enriched, involving signaling by interleukins, cytokine signaling in immune system, generic transcription pathway, and RNA polymerase II transcription. The targets mainly distributed in the lung, liver, and placenta, involving a variety of immune cells, such as T cells and B cells. The molecular docking results showed that core compounds such as wogonin, berberine, and baicalein had high affinity with tumor necrosis factor (TNF), insulin (INS), and tumor protein 53 (TP53). Conclusion The active compounds in HLJDD may have a therapeutic effect on COVID-19 through regulating multiple signal pathways by targeting genes such as vascular endothelial growth factor A (VEGFA), INS, interleukin-6 (IL-6), TNF, caspase-3 , TP53, and mitogen-activated protein kinase 3 (MAPK3).

Objective: To investigate the relationship between tumor-infiltrating lymphocytes (TILs) and the androgen receptor (AR) in human epidermal growth factor receptor 2 (HER-2)-positive breast cancer. Methods: Specimens of 448 patients with HER-2-positive breast cancer from the Tianjin Medical University Cancer Hospital between March 2018 and November 2018 were collected. TILs were pathologically evaluated. AR expression was immunohistochemically analyzed. The relationships among TILs, the AR, and clinicopathological parameters were determined. Results: There were 38.2% (171/448) patients with TILs non/low-infiltrated, 42.2% (189/448) with moderately infiltrated, and 19.6% (88/448) with high infiltration. AR was positive in 62.7%(281/448) of the patients. Spearman correlation analysis showed that TILs and the AR were negatively related (r=-0.140, P=0.003). TILs were significantly associated with the AR in estrogen receptor positive breast cancer (P=0.009). Conclusions: TILs and the AR were negatively related in HER-2-positive breast cancer, indicating that HER-2-positive breast cancer can be treated according to the different infiltration levels of TILs and AR expression.

Objective: To summarize the clinical manifestation and molecular characteristics of COQ6 mutation induced nephrotic syndrome, and to evaluate efficacy of CoQ₁₀ therapy. Method: Clinical data of the case with infantile nephrotic syndrome was summarized, including clinical manifestations, laboratory findings and family investigation. The patient received CoQ₁₀ 30 mg/(kg·d) therapy. Urine protein/creatinine ratio, serum albumin and creatinine were detected to assess the efficacy of the therapy. Result: (1) The 10 months old boy was presented with nephrotic level proteinuria and hypoalbuminemia. Extra-renal manifestations included cardiovascular abnormality, motor and mental retardation and unilateral ptosis. The patient had no consanguinity. A novel homozygous p. R360W mutation in COQ6 gene was identified and confirmed by next-generation sequencing and Sanger sequencing, respectively. Family analysis showed that homozygous p. R360W mutation in COQ6 gene was inherited from his parents. Missense p. R360W mutation was damaging by prediction online PolyPhen and SIFT software. After 2 months of CoQ₁₀ complementary therapy, the patient′s urine protein/creatinine ratio declined from 7.2 to 1.3, and decreased further to 0.01 mg/mg with normal albumin level and renal function within 3 months. Nephropathy remission was maintained and growth retardation improved significantly during the last follow-up. Nevertheless, the patient manifested with sensorineural deafness at the age of 2 years. (2) There were 6 different mutations in coenzyme Q₁₀ biosynthesis monooxygenase 6 (COQ6) in 13 individuals from 7 families by homozygosity mapping in the whole world. Each mutation was linked to early-onset SRNS with sensorineural deafness. Renal biopsy revealed FSGS in 7 cases and DMS in 1 case. Other manifestations included ataxia, seizures, facial dysmorphism, nephrolithiasis and growth retardation. Four patients received CoQ₁₀ supplementation and responded to the treatment. Conclusion Renal disease caused by recessive COQ6 gene mutation was nephrotic syndrome. The patient benefited from early CoQ₁₀ complement and reached nephropathy remission.

Objective: To investigate the clinical and genetic character of Chinese children with the aarF domain containing kinase 4 (ADCK4)-associated glomerulopathy. Methods: Applying next generation sequencing to detect possible gene mutation(renal disease associated monogene was pooled as one panel) in 69 children with steroid-resistant nephrotic syndrome (SRNS) or persistent proteinuria of unknown origin. Sanger sequencing was used to confirm the significant mutations found in the children and to validate these mutation sites in their patients. Using online software (PolyPhen2, SIFT, Mutation Taster) to predict whether the detected missense mutations were disease causing or not. Collecting and analyzing clinical data of children with ADCK4-associated glomerulopathy, which included onset age, clinical manifestation, and renal pathology. Results: The ADCK4 gene mutation was detected in 8 children with a positive rate of 11.6% (8 out of 69), among which 3 patients carried homozygous c.748G>C mutation, 3 patients carried homologous c.737G>A mutation, 1 patient carried compound heterozygous mutation(c.748G>C and c.737G>A), and 1 patient carried compound heterologous mutation(c.551A>G and c.737G>A). Collectively, there were only 3 mutation sites found in total 8 patients, in which the mutation sites of c.748G>C and c.737G>A had high detection frequency in these 8 patients. These 3 mutation sites were all missense mutation which were predicted to be disease causing by online software and not reported before. The average onset age was 6.5 years (2 years-11.75 years). Four patients presented with SRNS and the other 4 presented with persistent proteinuria. All 8 patients had no extrarenal manifestation, renal biopsy revealed focal segmental glomerulosclerosis (FSGS) in most patients, among which 3 cases had gone to end-stage renal disease (ESRD) at disease onset, and 2 cases progressed to ESRD 2 and 5 years after onset respectively. Seven patients had received glucocorticoid and/or immunosuppressive drug while only one patient getting partial response. All 8 patients were treated with large amount of coenzyme Q₁₀ (15 mg·kg^-1·d^-1) after definite diagnosis of ADCK4 mutation-some patients had acquired encouraging curative effect. Conclusions ADCK4-associated glomerulopathy is not rare especially in the children with SRNS. The onset age is relatively old and the extrarenal manifestation is less common. FSGS is a main pathology type. Patients usually have no response to immunosuppressive therapy, but may benefit from addition of large amount of coenzyme Q₁₀. Some patients may only manifest with insidious proteinuria, causing the early diagnosis to be difficult, which deserves more attention. Three new missense mutations expand disease causing mutation repertoire of ADCK4 gene, among which the two sites of c.748G>C and c.737G>A may be mutation hotspot of ADCK4-associated glomerulopathy in Chinese population, and need further study.