Total Tube Length Research Articles

Effects of propranolol on the biological behavior of human umbilical vein endothelial cells and the expression of SOX18, MMP-7, and VEGFA

To investigate the effects of propranolol on the proliferation, apoptosis, migration, and tube formation ability of human umbilical vein endothelial cells (HUVEC), as well as its impact on the expression of sex-determining region Y-box 18 (SOX18), matrix metalloproteinase-7 (MMP-7), and vascular endothelial growth factor A (VEGFA). HUVEC were treated with different concentrations of propranolol, and cell viability was assessed using the CCK-8 method to determine the optimal concentration and treatment duration. The experiment consisted of a control group and groups treated with different concentrations of propranolol (50, 100, 150 μmol/L). Apoptosis, migration, and tube formation of HUVEC were observed using flow cytometry, wound healing assays, and tube formation assays. Western blot and real-time quantitative PCR were used to detect the expression levels of SOX18, MMP-7, and VEGFA proteins and mRNA. Compared to the control group, the apoptosis rate in the propranolol treatment groups increased significantly (P<0.05), and it rose significantly with increasing drug concentration (P<0.05). The wound healing rate decreased in the propranolol treatment groups, and both the number of tube formation nodes and total tube length were reduced (P<0.05). The expression levels of SOX18, MMP-7, and VEGFA proteins and mRNA were downregulated in the propranolol treatment groups (P<0.05). Propranolol can inhibit the proliferation, migration, and tube formation ability of HUVEC and promote cell apoptosis, resulting in decreased expression levels of SOX18, MMP-7, and VEGFA.

Abstract 5400: CD160 regulates angiogenesis in activated human endothelial cells

Abstract Angiogenesis, the process of forming new blood vessels from pre-existing ones, plays a pivotal role in various physiological and pathological conditions. CD160, a cell surface receptor known for its modulatory function in the immune response, has recently garnered attention as a surface marker for activated endothelial cells. In this study, we investigate the anti-angiogenic effects of a novel anti-CD160 antibody. Using the tube formation assay, we evaluated the novel anti-CD160 antibody's ability to inhibit neovascularization potential in activated Human umbilical vein endothelial cells (HUVEC) in vitro. Our results revealed a significant reduction in total tube length, the number of branches, and closed networks, indicating the antibody's efficacy in impeding neovascularization. In addition, we explored the molecular mechanisms underlying CD160's anti-angiogenic properties, showing its ability to selectively decrease fibroblast growth factor-2-induced angiogenesis. Furthermore, we assessed the safety profile of our new anti-CD160 antibody by examining its impact on endothelial cell apoptosis. Encouragingly, our findings demonstrated no induction of apoptosis, suggesting the antibody's selective targeting of angiogenic processes without compromising endothelial cell viability, thus supporting CD160's vascular normalization properties. In conclusion, our research provides compelling evidence for the anti-angiogenic effects of the CD160 antibody, as evidenced by its inhibition of tube formation without inducing apoptosis in activated endothelial cells. These findings hold promising therapeutic implications for targeting angiogenesis in various pathological conditions, warranting further exploration for potential clinical applications. Keywords: CD160, Angiogenesis, Endothelial cells. HUVECs. Citation Format: Abdel-ilah AZIZ. CD160 regulates angiogenesis in activated human endothelial cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5400.

Hyaluronan-Sphingosine Polymersomes for Treatment of Ocular Neovascularization: Synthesis and Evaluation.

Ocular neovascularization is a hallmark of several sight-threatening diseases, including diabetic retinopathy and age-related macular degeneration. Currently, available treatments are limited and often associated with side effects. Therefore, a novel approach to ocular neovascularization treatment through utilization of polymersomes from self-assembled sphingosine-grafted hyaluronic acid (HA-Sph) amphiphilic polymers is presented. The polymersomes are generated in spherical morphologies and sizes between 97.95- 161.9nm with homogenous size distributions. Experiments reveal that HA-Sph polymersomes, with concentrations ≥150µg mL-1, significantly inhibit the proliferation of human umbilical vein endothelial cells (HUVECs), while concurrently promoting the proliferation of retinal pigment epithelial cells. The polymersomes demonstrate gradual disintegration in vitro, leading to sustained release of sphingosine, which prolongs the inhibition of HUVEC proliferation (from 87.5% at 24h to 35.2% viability at 96h). The efficacy of polymersomes in inhibiting angiogenesis is confirmed through tube formation assay, revealing a substantial reduction in tube length compared to the control group. The findings also validate the ocular penetration capability of polymersomes through ex vivo whole porcine eye ocular penetration study, indicating their suitability for topical administration. Potentially, HA-Sph polymersomes can be harnessed to develop intricate drug delivery systems that protect the retina and effectively treat ocular diseases.

Experimental Model Exposed to Bisphenol and Submitted to a High-Fat Diet and Related Morphologic Testicular Parameters Alterations Analysis.

To evaluate the morphological and stereological parameters of the testicles in mice exposed to bisphenol S and/or high-fat diet-induced obesity. Forty adult male C57BL/6 mice were fed a standard diet (SC) or high-fat diet (HF) for a total of 12 weeks. The sample was randomly divided into 4 experimental groups with 10 mices as follows: a) SC - animals fed a standard diet; b) SC-B - animals fed a standard diet and administration of BPS (25 μg/kg of body mass/day) in drinking water; c) HF: animals fed a high-fat diet; d) HF-B - animals fed a high-fat diet and administration of BPS (25 μg/Kg of body mass/day) in drinking water. BPS administration lasted 12 weeks, following exposure to the SC and HF diets. BPS was diluted in absolute ethanol (0.1%) and added to drinking water (concentration of 25 μg/kg body weight/day). The animals were euthanized, and the testes were processed and stained with hematoxylin and eosin (H&E) for morphometric and stereological parameters, including density of seminiferous tubules per area, length density and total length of seminiferous tubules, height of the tunica albuginea and the diameter of the seminiferous tubules. The images were captured with an Olympus BX51 microscope and Olympus DP70 camera. The stereological analysis was done with the Image Pro and Image J programs. Means were statistically compared using ANOVA and the Holm-Sidak post-test (p<0.05). The seminiferous tubule density per area reduced in all groups when compared with SC samples (p<0.001): HF (40%), SC-B 3(2%), and HF-B (36%). Length density was reduced significantly (p<0.001) in all groups when compared with SC group: HF (40%), SC-B (32%), and HF-B (36%). The seminiferous tubule total length was reduced (p<0.001) when compared to f HF (28%) and SC-B (26%) groups. The tubule diameter increased significantly (p<0.001) only when we compared the SC group with SC (54%) an SC-B (25%) groups and the tunica thickness increased significantly only in HF group (117%) when compared with SC-B (20%) and HF-B 31%. Animals exposed to bisphenol S and/or high-fat diet-induced obesity presented important structural alterations in testicular morphology.

The use of variable coil pitch of helical tube on the hydro-thermal performance improvement

The use of helical tubes in heat transfer appliances is desirable due to their better heat transfer characteristics, but the higher pressure drop decreases the overall performance. The variation of pitch design of a helical tube is proposed to alleviate this situation so that the pitch number does not remain constant in the total tube length. A total of six variable pitch numbers with three different diameters are proposed and investigated on the thermal and fluid characteristics. To better understand the helical tube efficiency, PEC (performance evaluation criteria) is selected as a performance indicator in the present work and simulations are performed in a laminar regime (100 ≤ Re≤ 1600) at a constant heat flux boundary condition using computational fluid dynamics. The numerical results show that variable radial pitch has higher effects on the overall performance than variable axial pitch, and it can intensify the helical tube performance by up to 10%. The results also indicate that increasing the tube diameter leads to heat transfer and friction factor increment while increasing the Reynolds number deteriorates the overall performance.

Three-dimensional morphometry of the testis in dog using design-unbiased stereology.

Testis is considered the main organ of the male reproductive system. Dogs are used as a suitable experimental model of testicular diseases in humans. From the veterinary aspect, several disorders have been reported to affect the testis in dogs. Thus, the objective of the present study was to investigate the morphometrical features of the dog testis using design-based stereology. The testes of six male dogs were used. Isotropic, uniform random sections were obtained and processed for light microscopy. Testicular total volume and the fractional volume of the seminiferous tubules, interstitial tissue and germinal epithelium were measured using the Cavalieri's estimator and the point counting system. Germinal epithelial surface area was estimated using test lines, and total length of seminiferous tubules was analysed using the counting frames. The total volume of testis was calculated 13.64 ± 1.94 cm3 . The relative volume fractions of the seminiferous tubules, interstitial tissue and germinal layer expressed as a percentage of total testicular volume were found to be 75.87 ± 6.11%, 23.68 ± 5.15% and 64.15 ± 4.82%, respectively. The surface area of the germinal layer was 915.25 ± 150.48 cm2 . The thickness of germinal layer was estimated to be 96.18 ± 10.72 μm. The total length of seminiferous tubules measured 290.8 ± 35.86 m. No statistical difference in investigated parameters was found between the left and right testes (p > 0.05). Our data might contribute to the male reproductive knowledge, help develop experimental studies in this field and possibly lead to advancement in the diagnosis and treatment of testicular diseases in the dog.

Thermodynamic and economic assessment of two-stage series organic Rankine cycle (TSORC) and regenerative TSORC (R-TSORC) for a solar project in hot, non-temperate climate

This paper provides a thermodynamic and economic assessment of two-stage series organic Rankine cycle (TSORC) and regenerative TSORC (R-TSORC) for a solar project in hot, non-temperate climate. The objective thermodynamic parameters include the net power output (Pnet), the thermal efficiency (ηth) and exergy efficiency (ηex), while the objective economic parameters include the electricity production cost (EPC), the payback period (PBP) and the rate of return on investment (ROROI). The total length of the receiver tube has been also considered as objective parameter. The two solar ORCs were compared on the basis of the same thermal potential generated by the solar system. The results show that, for the same thermal potential of energy source, the R-TSORC requires more mass flow rate of heat transfer fluid, but with a total length of receiver tube less than the TSORC. However, the Pnet, ηth, ηex, EPC, PBP and ROROI of R-TSORC are more competitive than those of the TSORC. In addition, it was found that the EPC of R-TSORC is lower than the electricity self-generation costs for industrial companies in Cameroon. Therefore, the R-TSORC can be effectively exploited in the micro solar plants of hot, non-temperate regions where the electricity issues remain problematic.

DEVELOPED SURFACES AS A FACTOR FOR OPTIMIZING THE DESIGN OF HEAT EXCHANGERS

Optimization of the geometric parameters of heat exchangers can be carried out according to many parameters. One of the most important are geometric dimensions. The development of an optimized heat exchanger design using experimental planning methods is an urgent task. This allows you to minimize the cost of materials for the manufacture of devices and transfer heat most efficiently.&#x0D; Intensification of heat exchange is always given great attention for any branch of industry and technology. High requirements are put forward to the structures of heat exchange equipment, which are related to the reduction of their mass, occupied volume, etc. A promising direction is the use of heat exchange surfaces with a large area, that is, developed, which is achieved by finning the primary surface. The optimal design of the surface development is determined by the values of the heat transfer coefficients from the hot coolant to the dividing wall of the heat exchanger tube and from the wall to the cold coolant. The most widely used are ribbed surfaces with knurled ribs, which are quite convenient in production and further operation&#x0D; The purpose of the work is to determine the influence of such factors as the length of one finned tube, the bearing diameter of the finned tube and the finning ratio on the optimal structural performance of the compressed air heater based on the minimum length of the pipe system.&#x0D; In terms of influence, the length of one tube is the most important, and the fin ratio is of secondary importance. With a significant increase in the finning ratio of the pipes, the total length of the pipes decreases.&#x0D; The developed technique makes it possible to determine the optimal value of such a parameter as the total length of finned tubes. Also, on the basis of the obtained results, it is possible to develop an appropriate design of the heat exchanger with the accepted number of tubes transverse to the flow of the heat carrier that is heated. With the help of the developed methodology, it is possible to analyze the value of the length of the tubular system of the heat exchanger with various combinations of the above factors and to optimize its design in a fairly simple formulation.

Utilizing waste heat gasoline engine in the design and fabrication of a fin and tube evaporator for the Organic Rankine Cycle (ORC)

The excessive consumption of fossil fuels is causing environmental problems, which can be addressed by utilizing renewable energy sources such as hydro energy, biomass, solar heat, geothermal, and waste heat. In particular, the exhaust gas from gasoline engines presents an opportunity for energy recovery, as only 25% of the energy is utilized while the remaining 75% is wasted. A fin and tube type evaporator was designed, manufactured, and tested to utilize this exhaust gas in an Organic Rankine Cycle (ORC) system. The evaporator was designed with an outer tube diameter of 9.525 mm and a total tube length of 41.4 m, featuring 90 tubes and 135 fins with a total area of 14,325 m2. It achieved an average effectiveness of 94.33%. The results showed that the waste heat from the exhaust gas of a gasoline engine could be used as a source of energy in an ORC system with an efficiency of 2.13%. It results in 7.02 kJ/s of energy absorbed by the evaporator and a net power generated of 0.15 kJ/s. This research demonstrates the potential for utilizing waste heat from gasoline engines as an energy source to generate electricity.

Stem cell-derived exosomes from human exfoliated deciduous teeth promote angiogenesis in hyperglycemic-induced human umbilical vein endothelial cells.

To investigate the angiogenesis in human umbilical vein endothelial cells (HUVEC) under high glucose concentration, treated with exosomes derived from stem cells from human exfoliated deciduous teeth (SHED). SHED-derived exosomes were isolated by differential centrifugation and were characterized by nanoparticle tracking analysis, transmission electron microscopy, and flow cytometric assays. We conducted in vitro experiments to examine the angiogenesis in HUVEC under high glucose concentration. Cell Counting Kit-8, migration assay, tube formation assay, quantitative real-time PCR, and immunostaining were performed to study the role of SHED-derived exosomes in cell proliferation, migration, and angiogenic activities. The characterization confirmed SHED-derived exosomes: size ranged from 60-150 nm with a mode of 134 nm, cup-shaped morphology, and stained positively for CD9, CD63, and CD81. SHED-exosome significantly enhanced the proliferation and migration of high glucose-treated HUVEC. A significant reduction was observed in tube formation and a weak CD31 staining compared to the untreated-hyperglycemic-induced group. Interestingly, exosome treatment improved tube formation qualitatively and demonstrated a significant increase in tube formation in the covered area, total branching points, total tube length, and total loop parameters. Moreover, SHED-exosome upregulates angiogenesis-related factors, including the GATA2 gene and CD31 protein. Our data suggest that the use of SHED-derived exosomes potentially increases angiogenesis in HUVEC under hyperglycemic conditions, which includes increased cell proliferation, migration, tubular structures formation, GATA2 gene, and CD31 protein expression. SHED-exosome usage may provide a new treatment strategy for periodontal patients with diabetes mellitus.

Sulfasalazine exposure during pregnancy and lactation: reproductive outcomes in male rat offspring.

Sulfasalazine (SAS) is a drug prescribed for pregnant and breastfeeding women with chronic inflammatory bowel diseases. SAS treatment induces transitory infertility in both adult men and male rats. Although SAS crosses the placenta and passes into maternal milk, the consequences of maternal SAS exposure on the reproductive development of male offspring needs further study. The current study evaluated whether maternal SAS exposure interferes with the reproductive development of male rat offspring in the neonatal, infant, pubertal and adulthood periods. Pregnant Wistar rats (n =10/group) received 300mg/kg/day of SAS dissolved in carboxymethyl cellulose (CMC), by gavage, from gestational day 0 to lactation day 21, and 3mg/kg/day of folic acid during gestation. The control group received CMC. During puberty, maternal SAS exposure increased the total length of seminiferous tubules, and round cells were observed in the lumen of caput and cauda epididymis. Moreover, SAS induced oxidative stress-related alterations in the testes of infant and adolescent rats. Although maternal SAS treatment caused reproductive alterations in infant and adolescent male rats, in adulthood, there were no impairments in sperm parameters that could compromise fertility. This study investigated the consequences of maternal exposure to SAS on the reproductive development of male rat offspring from birth to adulthood, employing a human-relevant dose. Thus, this study provides information for better understanding of SAS treatment during critical periods of development.

Morroniside Regulates Endothelial Cell Function via the EphrinB Signaling Pathway after Oxygen-Glucose Deprivation In Vitro.

Proangiogenic treatment is a potential treatment for acute myocardial infarction (AMI). Morroniside was previously discovered to increase post-AMI angiogenesis in rats as well as the proliferation of rat coronary artery endothelial cells (RCAECs). However, the effects of morroniside on other endothelial cell (EC) functions and underlying mechanisms are unknown. To further clarify the vascular biological activity of morroniside, this work focused on investigating how morroniside influenced endothelial cell functions, such as cell viability, tube formation capacity, migration, and adhesion, and to explore the signaling pathway. Oxygen-glucose deprivation causes ischemic damage in RCAECs (OGD). In vitro investigations were carried out to explore the involvement of morroniside in EC function and pathways mediated by ephrinB. The results revealed that the number of BrdU+ cells and cell viability in the high-dose group were considerably greater than in the OGD group (P < 0.05). The ability of tube formation evaluated by total tube length, tube-like structural junction, and tube area was significantly higher in the morroniside group than in the OGD group (P < 0.001). Morroniside considerably improved migration and adhesion abilities compared to OGD group (P < 0.05, P < 0.01, P < 0.001). The protein expression levels of the ephrinB reverse signaling pathway were substantially greater in the morroniside group than in the OGD group (P < 0.05, P < 0.01). In conclusion, the current study demonstrated that morroniside modulates endothelial cell function via ephrinB reverse signaling pathways and provided a novel insight and therapeutic strategy into vascular biology.

Treatment with topiramate in rats during childhood causes testicular structural impairment at adulthood.

Topiramate (TOP) is a psychotropic drug prescribed for the treatment of epilepsy in children older than 2 years of age and for migraine prophylaxis in adolescents. There is evidence that TOP promotes negative effects on the reproductive system of male rats. This study aimed to evaluate the immediate and late treatment effects of TOP during childhood and adolescence on the male rat reproductive system. Two experimental groups received 41 mg/kg of TOP daily, by gavage, from postnatal day (PND) 16 to 28 (TOPc group) or from PND 28 to 50 (TOPa group). Control groups (CTRc group or CTRa group) received water daily. Half of the anim-als were evaluated 24 h after the end of treatment (PND 29 and PND 51, respectively) and the remainder were evaluated in adulthood (PND120). The following parameters were determined: anogenital distance, sperm evaluation, testis' histomorphometry and plasma testosterone concentration. At PND 120, the volume (CTRc:62.58 ± 2.13; TOPc: 54.54 ± 2.10*%, p = 0.018) and total length (CTRc: 25.48 ± 1.61; TOPc: 18.94 ± 2.41*, p = 0.035) of seminiferous tubules were decreased and the volume of interstitial tissue (CTRc:37.41 ± 2.13; TOPc: 45.45 ± 2.09*%, p = 0.018) and number of Leydig cells/testis (CTRc: 277.00 ± 36.70; TOPc: 400.20 ± 13.23*, p = 0.013) were increased in the TOPc group. The other parameters remained similar between the groups. Therefore, the present study contributes to our understanding that childhood treatment with TOP has an impact on the rat reproductive system in adulthood, suggesting that this period is more sensitive to TOP exposure than adolescence.

Bacillus thuringiensis affects reproductive capacity of adult rat offspring

ABSTRACT We investigated the effects of B. thuringiensis-based biological insecticides, XenTari and Dipel, and deltamethrin on the reproductive development of pups of pregnant rats. Twenty 90-day-old pregnant rats were divided randomly onto four equal groups: control group (GC) administered only water; XenTari group (GX) administered 1 mg XenTari (containing Cry1Ac toxin of B. thuringiensis)/100 g body weight; Dipel group (GDi) administered 1 mg Dipel (containing Cry1Aa, Cry1Ab and Cry1Ac toxins of B. thuringiensis)/100 g body weight; and a deltamethrin group (GDe) administered 2 mg deltamethrin (0.08 ml Keshet 25EC)/kg body weight as a positive control. Insecticides were administered by gavage at doses of 1 mg/100 g/day (GX and GDi), and 2 mg/kg/day (GDe) during pregnancy and lactation. Treatment with both biologic and synthetic insecticides reduced the weight gain of the mothers. The biological insecticides reduced the number, weight and length, and increased malformation and mortality of the offspring. In female offspring for all three groups administered insecticides, opening of the vagina was delayed, metestrus was increased and estrogen and progesterone levels were reduced compared to proestrus, estrus and metestrus of the cycle. The ovaries of female offspring of all three groups administered insecticides contained numerous tertiary and atretic follicles, few corpora lutea, primary and secondary follicles, and reduced estrogen receptors compared to controls. In male offspring, all three groups exposed to insecticides exhibited reduced testosterone levels. Histopathological changes in the testes including vacuolation and desquamation of the seminiferous epithelium were observed only in the GX and GDi groups. The number of androgen receptors was reduced significantly in the testes and testicular morphometry revealed reduced tubule diameter, height of the seminiferous epithelium and total tubule length compared to the control. The biological insecticides, XenTari and Dipel, administered in sublethal doses to pregnant rats, caused reproductive changes in the offspring similar to those of the insecticide, deltamethrin.

Recombinant Human Arresten and Canstatin Inhibit Angiogenic Behaviors of HUVECs via Inhibiting the PI3K/Akt Signaling Pathway.

Angiogenetic inhibitors are crucial in tumor therapy, and endogenous angiogenesis inhibitors have attracted considerable attention due to their effectiveness, safety, and multi-targeting ability. Arresten and canstatin, which have anti-angiogenesis effects, are the c-terminal fragments of the α1 and α2 chains of type IV collagen, respectively. In this study, human arresten and canstatin were recombinantly expressed in Escherichia coli (E. coli), and their effects on the proliferation, migration and tube formation of human umbilical vein endothelial cells (HUVECs) were evaluated. Regarding the cell cycle distribution test and 5-ethynyl-2′-deoxyuridine (EdU) assays, arresten and canstatin could repress the proliferation of HUVECs at a range of concentrations. Transwell assay indicated that the migration of HUVECs was significantly decreased in the presence of arresten and canstatin, while tube formation assays suggested that the total tube length and junction number of HUVECs were significantly inhibited by these two proteins; moreover, they could also reduce the expression of vascular endothelial growth factor (VEGF) and the phosphorylation levels of PI3K and Akt, which indicated that the activation of the 3-kinase/serine/threonine-kinase (PI3K/Akt) signaling pathway was inhibited. These findings may have important implications for the soluble recombinant expression of human arresten and canstatin, and for the related therapy of cancer.

Fibroblast expression of CD248 may contribute to exacerbation of microvascular damage during systemic sclerosis.

CD248 is a glycoprotein, highly expressed on pericytes and fibroblasts (FBs), that is implicated in the fibrotic process. During angiogenesis, CD248 can promote vessel regression, binding multimerin-2 (MMRN-2). Thus, we investigated the expression of MMRN-2 in systemic sclerosis (SSc)-skin and of CD248 in isolated SSc-FBs. The anti-angiogenic property of CD248+ SSc-FBs was evaluated by co-culturing these cells with healthy control endothelial cells (HC-ECs). The apoptotic effect of CD248 on HC-ECs was evaluated. Finally, the ability of CD248 to prevent activation of VEGF receptor 2 (VEGFR2) was assessed. By IF, MMRN-2 was investigated in SSc-skin and CD248 in SSc FBs. The anti-angiogenic property of CD248+ SSc-FBs was evaluated by HC-ECs/SSc-FBs co-cultures. Lentiviral-induced CD248 short-hairpin RNA delivery was employed for loss-of-function studies in SSc-FBs. HC-ECs were cultured in the presence of CD248 to assess apoptosis by IF and VEGFR2 phosphorylation by western blot. MMRN-2 expression was increased in skin SSc-ECs, whereas CD248 expression was increased in SSc-FBs. Functionally, CD248+-SSc-FBs suppressed angiogenesis in the organotypic model, as assessed by the reduction in total tube length of HC-ECs. This anti-angiogenetic behaviour was reversed by CD248 silencing. Furthermore, the presence of CD248 promoted the apoptosis of HC-ECs. Finally, CD248 prevented activation of VEGFR2 by reducing its phosphorylation after VEGF stimulation. CD248 was anti-angiogenic in vitro due to a reduction in tube formation and to induction of apoptosis of ECs. Increased expression of CD248 in SSc could contribute to the microvascular rarefaction observed at the tissue level in SSc. Our results suggest a pathogenic role for CD248-MMRN-2 in SSc.

Demonstration study on ground source heat pump heating system with solar thermal energy storage for greenhouse heating

In this study, a demonstration project of a ground source heat pump (GSHP) heating system with seasonal solar thermal energy storage (SSTES) and diurnal solar thermal energy storage (DSTES) is constructed for greenhouse heating. In the non-heating season, the SSTES overcomes the thermal imbalance of GSHP heating for agricultural greenhouses. While in the heating season, the DSTES undertakes part of the heating load of greenhouses, reduces GSHP heating electric energy consumption and improves the annual coefficient of performance of heating system COPsys,y. The experimental data illustrate that the soil temperature of ground heat exchanger (GHE) area is about 0.3 K higher than the initial soil temperature at the end of SSTES, and the COPsys,y of the proposed heating system is 14.3 % higher than that of bank control experiment. The above results demonstrate that the proposed heating system is favorable for greenhouses in cold regions. Further, coupling DSTES can reduce the rated capacity of GSHP and the total length of GHE tube for the newly designed heating system. In addition, the recommended values of two key operating parameters are given based on the experimental data. This study can shed a light on clean and efficient heating for greenhouses in cold regions and provide data support for related research.

Birthweight leads to seminal and testicular morphofunctional commitment in sexually mature boars

Given the importance of males as semen donors for artificial insemination (AI) and the high incidence of low birthweight piglets at commercial farms, the impact of birthweight on fertility in boars deserves special attention. The aim of this study was to evaluate testicular morphofunctional parameters and semen characteristics in different birthweight boars. Forty littermate males were selected at birth and divided into two experimental groups, according to birthweight: high (HW, birthweight ranging from 1.80 to 2.15 kg, n = 20) and low (LW, birthweight ranging from 0.75 to 1.10 kg, n = 20). At 170 days of age, a sub-set of 24 littermate boars (n = 12 HW and n = 12 LW) were randomly selected for semen collection, which was performed once a week, at a 15-day interval, during five weeks. At 300 days of age, boars were orchiectomized, and the testis processed for histological and molecular analyses. The HW group was heavier and presented larger testes compared to LW animals (P < 0.05). Despite that, birthweight did not significantly affect semen volume or sperm quality parameters (concentration, motility, vigor or morphology), although LW boars produced 38.2% fewer total sperm and 24% lower semen concentration, leading to 36.8% less inseminating doses. The histomorphometrical evaluation showed that seminiferous tubules diameter and germinal epithelium height were similar between experimental groups. However, LW boars presented shorter seminiferous tubules and, consequently, fewer Sertoli cells per testis (P 0.05). Even though plasma testosterone levels were equivalent in both birthweight groups, LW testis presented less androgen receptors (P < 0.05). Additionally, birthweight was positively correlated with total seminiferous tubule length and number of Sertoli cells (P < 0.01), and with body and testis weights (P < 0.01). Taken together, even though adult LW boars showed no evident semen pathologies or spermatogenesis commitment, mature HW males have the potential to produce more spermatozoa, consequently more semen doses per ejaculate, being more valuable to an industry that relies on AI.

Effects and mechanism of negative pressure microenvironment on the neogenesis of human umbilical vein endothelial cells

Effects and mechanism of negative pressure microenvironment on the neogenesis of human umbilical vein endothelial cells

Establishment and biological effect evaluation of prevascularized porous β-tricalcium phosphate tissue engineered bone

To evaluate the biological effect on vascularization during bone repair of prevascularized porous β-tricalcium phosphate (β-TCP) tissue engineered bone (hereinafter referred to as prevascularized tissue engineered bone), which was established by co-culture of endothelial progenitor cells (EPCs) and bone marrow mesenchymal stem cells (BMSCs) based on tissue engineering technology. EPCs and BMSCs were isolated from iliac bone marrow of New Zealand white rabbits by density gradient centrifugation and differential adhesion method. The cells were identified by immunophenotypic detection, BMSCs-induced differentiation, and EPCs phagocytosis. After identification, the third-generation cells were selected for subsequent experiments. First, in vitro tubule formation in EPCs/BMSCs direct contact co-culture (EPCs/BMSCs group) was detected by Matrigel tubule formation assay and single EPCs (EPCs group) as control. Then, the prevascularized tissue engineered bone were established by co-culture of EPCs/BMSCs in porous β-TCP scaffolds for 7 days (EPCs/BMSCs group), taking EPCs in porous β-TCP scaffolds as a control (EPCs group). Scanning electron microscopy and laser scanning confocal microscopy were used to observe the adhesion, proliferation, and tube formation of cells. Femoral condyle defect models of 12 New Zealand white rabbits were used for implantation of prevascularized tissue engineered bone as the experimental group ( n=6) and porous β-TCP scaffold as the control group ( n=6). The process of vascularization of β-TCP scaffolds were observed. The numbers, diameter, and area fraction of neovascularization were quantitatively evaluated by Microfill perfusion, Micro-CT scanning, and vascular imaging under fluorescence at 4 and 8 weeks. The isolated cells were BMSCs and EPCs through identification. EPCs/BMSCs co-culture gradually formed tubular structure. The number of tubules and branches, and the total length of tubules formed in the EPCs/BMSCs group were significantly more than those in the EPCs group on Matrigel ( P<0.05) after 6 hours. After implanting and culturing in porous β-TCP scaffold for 7 days, EPCs formed cell membrane structure and attached to the material in EPCs group, and the cells attached more tightly, cell layers were thicker, the number of cells and the formation of tubular structures were significantly more in the EPCs/BMSCs group than in the EPCs group. At 4 weeks after implantation, neovascularization was observed in both groups. At 8 weeks, remodeling of neovascularization occurred in both groups. The number, diameter, and area fraction of neovascularization in the experimental group were higher than those in the control group ( P<0.05), except for area fraction at 4 weeks after implantation ( P>0.05). The prevascularized tissue engineered bone based on direct contact co-culture of BMSCs and EPCs can significantly promote the early vascularization process during bone defects repair.