Application of acoustic agglomeration to enhance air filtration efficiency in air-conditioning and mechanical ventilation (ACMV) systems.

The recent episodes of haze in Southeast Asia have caused some of the worst regional atmospheric pollution ever recorded in history. In order to control the levels of airborne fine particulate matters (PM) indoors, filtration systems providing high PM capturing efficiency are often sought, which inadvertently also results in high airflow resistance (or pressure drop) that increases the energy consumption for air distribution. A pre-conditioning mechanism promoting the formation of particle clusters to enhance PM capturing efficiency without adding flow resistance in the air distribution ductwork could provide an energy-efficient solution. This pre-conditioning mechanism can be fulfilled by acoustic agglomeration, which is a phenomenon that promotes the coagulation of suspended particles by acoustic waves propagating in the fluid medium. This paper discusses the basic mechanisms of acoustic agglomeration along with influencing factors that could affect the agglomeration efficiency. The feasibility to apply acoustic agglomeration to improve filtration in air-conditioning and mechanical ventilation (ACMV) systems is investigated experimentally in a small-scale wind tunnel. Experimental results indicate that this novel application of acoustic pre-conditioning improves the PM2.5 filtration efficiency of the test filters by up to 10% without introducing additional pressure drop. The fan energy savings from not having to switch to a high capturing efficiency filter largely outstrip the additional energy consumed by the acoustics system. This, as a whole, demonstrates potential energy savings from the combined acoustic-enhanced filtration system without compromising on PM capturing efficiency.

[Apoptosis of sperm induced by murine cytomegalovirus infection and its mechanism regulated by sperm mitochondria: experiment with mice].

OBJECTIVE: To study the effects of murine cytomegalovirus (MCMV) infection on mature sperm apoptosis in mice, and to explore the mechanism of MCMV-induced apoptosis regulated by mitochondria. METHODS: MCMV was inoculated into the testes of 15 BALB/c mice to establish acute MCMV infection models and 15 mice were used as controls. 1, 2, 4, 6, and 9 days after the infection 3 mice from each group were killed. Flow cytometry was used to observe the apoptosis of sperms. Laser scanning confocal microscopy was performed to examine the mitochondrial membrane potential (delta psi psi m) of sperm. The mitochondria ultrastructure of sperm was observed under electron microscope. RESULTS: The sperm apoptotic ratebeganto increase from day 2 after inoculation (D2 PI), peaked to the level of (39.3 +/- 1.0)% compared with that of the control group on D4 PI, and then fell-off (F = 362.822, P < 0.05). The delta psi m of sperm began to increase on D1 PI at the level of (74.0 +/- 1.4), began to decrease on D2 PI [( 63.0 +/- 2.2)], dropped to the minimum on D4 PI [(40.2 +/- 2.3)], then ascended slowly again (F = 32.257, P < 0.05). The mitochondria ultrastructure of sperm showed damage after MCMV infection that was especially severe from D2 PI to D6 PI. CONCLUSION: MCMV acute infection in reproductive organ induces apoptosis of mature sperm in the cauda epididymidis. Sperm mitochondria participate in and regulate initiatively the apoptosis of sperm.

Candida albicans and filtrates interfere with human spermatozoal motility and alter the ultrastructure of spermatozoa: an in vitro study.

The in vitro effects of Candida albicans and its filtrates on the motility and ultrastructure of human spermatozoa from healthy donors were studied. A significant reduction in sperm progressive motility and signs of membrane alteration, directly related to contact time were observed. Distinct adhesion of spermatozoa to C. albicans and agglutination were observed. Light and transmission electron microscopy examinations showed that spermatozoa attached to C. albicans mainly via the head. Multiple ultrastructural lesions were present, which were the possible morphological reasons for spermatozoan immobilization observed in the present study. It is concluded that C. albicans as well as its filtrates had an inhibitory effect on human sperm motility and impaired the ultrastructure of human spermatozoa, which could be associated with male infertility.

[Resistant effect of water decoction of root of Crataegus cuneata on male infertility induced by GTW in rats].

OBJECTIVE: To observe the effects of water decoction of the root of Crataegus cuneata on infertility induced by multi-glucoside of Tripterygium wilfordii (GTW) in rats. METHOD: Male adult rats were randomly divided into five groups, which were treated via gastric gavage of distilled water (1 mL x kg(-1)) , solution of GTW (10 mg x kg(-1)) and three doses of water decoction of root of C. cuneata (1.8, 5.4, 18 g x kg(-1)) + GTW (10 mg x kg(-1)), respectively. 8 weeks later, GTW was stopped and the decoction and water continued for another 4 weeks. And then, all the male rats were copulated with adult female rats. The rates of pregnancy, average numbers of embryos and luteum of female rats, relative weights of reproductive organs, sperm counts, sperm motility and viability were compared among all the groups. The histology and ultrastructure of testis and epididymis were observed, while the concentrations of follicle stimulating hormone (FSH), luteinizing hormone (LH) and testostorone (T) in serum and T in testicular homogenate were detected by radioimmunoassay. RESULT: Compared with those in GTW model group, the embryo numbers, the relative weight of testis and epididymis and sperm counts and motility in C. cuneata groups were increased obviously (P < 0.05). After treatment, the morphological damages of seminiferous tubules and sperms were recovered, while concentrations of T in testicular homogenate were also significantly increased (P < 0.01). CONCLUSION: C. cuneata could relieve the reproductive lesions induced by GTW, and hence improve the uberty of the male infertile model rats.

[Effects of testis murine cytomegalovirus infection on sperm acrosome reaction and spermatic function of membrane in mice].

OBJECTIVE: To explore the effects of testis murine cytomegalovirus (MCMV) infection on mature sperm acrosome reaction and spermatic function of membrane in mice. METHODS: BALB/c mice without MCMV infection were randomly devided into two groups: an experimental group (48 mice) and a control group (30 mice). The mice in the control group were treated by inoculation DMEM without MCMV into testis, while those in the experimental one were directly inoculated with MCMV into testis. Mice in two groups were sacrificed separately at 1, 2, 4, 6, 9, 14 d post inoculation (D1, 2, 4, 6, 9, 14 PI), and the MCMV M83 mRNA gene was detected inside the testes by in situ hybridization (ISH) with one episode MCMV late-mRNA probe labeled with digoxin, meanwhile acrosome reaction and the function of membrane of mature sperms in the epididymis tails was measured. RESULTS: The positive signal of ISH of MCMV was mainly founded in the two kinds of testicular cells (spermatogenic cells and Leydig cells) in the experimental group. Compared with that of the control group, the sperm acrosome reaction in the experimental group was decreased significantly by the rate from (71 +/- 6)%, (70 +/- 7)% to (58 +/- 9)%, (56 +/- 9)% (P < 0.05) separately on D2 PI and D4 PI. And the sperm membrane hypo-osmotic swelling was decreased significantly by the rate from (60 +/- 7)%, (50 +/- 4)% to (48 +/- 9)%, (38 +/- 8)% (P < 0.05) separately also on D2 PI and D4 PI. CONCLUSION: The model of CMV infection in murine testis was established. The sperm acrosome reaction and function of membrane in mice might be descented significantly by MCMV infection in the early period, which shows that MCMV infection might influent the sperm's function.

[Experimental study on effects of testis murine cytomegalovirus infection on sperm viability in mice].

OBJECTIVE: To explore the effects of testis murine cytomegalovirus (MCMV) infection on mature sperm viability in mice. METHODS: BALB/c mice without MCMV infection, screened by ELISA, were randomly divided into two groups: an experimental group (n = 64) and a control group (n = 40). The former were directly inoculated with MCMV into the testis, while the latter treated by inoculation of DMEM without MCMV. The mice in both of the groups were sacrificed respectively at 1, 2, 4, 6, 9, 14, 21, 38 d postinoculation (D1, 2, 4, 6, 9, 14, 21, 38 PI), the testis was examined histopathologically, and meanwhile the viability of mature sperms in the epididymis cauda was measured. RESULTS: MCMV basophil inclusion bodies were found in the Leydig cells in the experimental group, and spermatogenic cells were vacuolated and arranged disorderly. Compared with the control group, the sperm viability in the experimental group was decreased significantly by 71.42% to 56.04% (P < 0.05) on D1 PI. CONCLUSION: The sperm viability in mice might be descended significantly by MCMV infection in the early period, but restored to normal with time. This shows that MCMV infection might influence procreation transiently.

[The experimental study of guinea pig cytomegalovirus infection in the kidney of the pup of guinea pig].

OBJECTIVE: To study the relationship of guinea pig cytomegalovirus (GPCMV) infection with the outcome of pregnancy by the kidney of guinea pig (GP). METHODS: Twenty first-trimester gestation GPs were randomly selected, intraperitoneally inoculated with GPCMV. Then female GPs and the pups were killed within 24 h after delivery. By in situ hybridization (ISH) with three phases GPCMV late-mRNA probes labeled by digoxin, the virus load and its distribution were screened inside the pup's kidney. RESULTS: Twenty GPs totally conceived 63 pups. Among them, 42 had normal outcome and lived longer than 24 h; 21 had abnormal outcome such as abortion, fetal death, et al. By in situ hybridization, the infection rate of normal pups was 7.1% (3/42) and the average optical density (A) was 0.105 +/- 0.052. The infection rate of abnormal pups was 28. 6% (6/21) and the A was 0.158 +/- 0.047. The difference of the A was significant (t = 2.57, P < 0.05). The positive signal of ISH was mainly distributed in the epithelium of renal tubule and collecting duct. CONCLUSION: It is concluded that the late-mRNA mainly expressed in the epithelium of renal tubule and collecting duct and the expression level was related with the abnormal pregnancy outcome.