centrifugation technique
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2021 ◽  
Author(s):  
Lingling Salang ◽  
Kanok Seejorn ◽  
Thanida Pongsritasana

Abstract Objectives To evaluate the effect of different incubation temperature between room (26–28˚c) and body (37 ˚c) temperature on percentage of progressive sperm motility and the optimal incubation period before intrauterine insemination. Methods Seventy-one normal semen samples under WHO 2010 criteria were recruited. All semen was prepared with Density Gradient Centrifugation technique (DGC) and divided into two groups to evaluate sperm motility at 60 min of incubation time. First group: prepared semen was incubated in room temperature (26˚-28˚c) and second group: prepared semen was incubated in body temperature (37°c). Moreover, each group is divided into 4 items for compare sperm motility between both groups in same of incubation time and evaluate the optimal incubation time between the items in the same groups. Results Spermatozoa incubated at body temperature had a significantly higher percentage of progressive sperm motility than those incubated at room temperature (89.62 ± 8.02 vs 85.97 ± 9.42; p < 0.01). The optimal incubation time at room temperature was 30 minutes and at body temperature was 60 minutes. These results suggest that spermatozoa incubated at 37°C for 60 minutes were more likely to have better sperm motility functions for IUI. Conclusion These results suggest that spermatozoa incubated at 37°C for 60 minutes were more likely to be effective for use in IUI in terms of sperm motility functions.


2021 ◽  
Vol 7 (1) ◽  
pp. eabc0467
Author(s):  
Yuyang Gu ◽  
Chuyi Chen ◽  
Zhangming Mao ◽  
Hunter Bachman ◽  
Ryan Becker ◽  
...  

Liquid droplets have been studied for decades and have recently experienced renewed attention as a simplified model for numerous fascinating physical phenomena occurring on size scales from the cell nucleus to stellar black holes. Here, we present an acoustofluidic centrifugation technique that leverages an entanglement of acoustic wave actuation and the spin of a fluidic droplet to enable nanoparticle enrichment and separation. By combining acoustic streaming and droplet spinning, rapid (<1 min) nanoparticle concentration and size-based separation are achieved with a resolution sufficient to identify and isolate exosome subpopulations. The underlying physical mechanisms have been characterized both numerically and experimentally, and the ability to process biological samples (including DNA segments and exosome subpopulations) has been successfully demonstrated. Together, this acoustofluidic centrifuge overcomes existing limitations in the manipulation of nanoscale (<100 nm) bioparticles and can be valuable for various applications in the fields of biology, chemistry, engineering, material science, and medicine.


Author(s):  
Varisara Deerattrakul ◽  
Wisit Hirunpinyopas ◽  
Nuttapon Pisitpipathsin ◽  
Thanit Saisopa ◽  
Montree Sawangphruk ◽  
...  

This work explores the capacitance and ionic transport properties of size dependent graphene (from 100 nm to 1 μm) prepared through the liquid phase exfoliation of graphite in which the size of graphene was finely selected using a multi-step centrifugation technique.


2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Zong-Tao Li ◽  
Jia-Yong Liang ◽  
Jia-Sheng Li ◽  
Jie-Xin Li ◽  
Yong Tang

Abstract Inverted packaging structure is a promising alternative for thermal isolation between light-emitting diode (LED) chips and quantum dot (QD) converters with effective heat dissipation. However, serious reflection loss occurs at the lead frame owing to the inverted bonding of LED chips. In this study, the scattering nanoparticles-induced reflection effect has been developed to enhance the optical efficiency of inverted QD-LEDs combined with the centrifugation technique. The strong back-scattered effect of boron nitride (BN) nanoparticles with a thin columnar structure is chosen for reflection enhancement according to the ray-tracing and finite different time-domain simulations. Furthermore, a centrifugation technique is introduced to control the equilibrium geometry of the BN-incorporating reflector (BNR) by changing the centrifugal speed. Results indicate that the luminous flux of inverted QD/BNR-LEDs using the optimized concave BNR structure largely increases by 82.8% compared with reference inverted QD-LEDs. The great enhancement is attributed to the light concentrated effect of the concave geometry and the strong diffusion reflection ability of BN scattering nanoparticles. Consequently, the smart design on reflection properties of inverted QD-LEDs is critical for achieving high optical performances.


Author(s):  
P. Kalyani ◽  
G. Kaarthikeyan ◽  
M. P. Santhosh Kumar

Platelet rich plasma (PRP) is a novel method of using plasma concentrated with platelets for wound healing and tissue regeneration. Platelet rich plasma is prepared from the venous blood using a differential centrifugation technique. It involves a separation spin and a concentration spin, yielding platelet rich plasma. PRP products have been classified into 4 types depending upon major cell constituent and fibrin density upon activation. These are as follows: Pure PRP, Leukocyte and PRP, Pure PRF, Leukocyte and PRF. PRF differs from PRP in that it is rich in a high density fibrin network after activation. PRP is abundant in a variety of growth factors such as VEGF, PDGF, TGF, EGF, and Interleukin-1. Literature consists of reports by different authors about the platelet yield of PRP centrifuged by different systems. A number of factors have also been quoted to influence the platelet concentration in platelet rich plasma. Hence, the aim of this review is to discuss the platelet concentration in PRP centrifuged by different systems and to observe for variations if any.


Author(s):  
Mohammad Sekhavati ◽  
Ashraf Mohabati Mobarez ◽  
Seyed Davar Siadat ◽  
Mojtaba Noofeli

Background and Objectives: There are many pertussis outbreaks which is mainly due to the reduction in the immunity of acellular pertussis (aP) vaccines. Therefore, there is a crucial necessity to develop a new generation of pertussis vaccine. Pre- ceding researches have shown that Bordetella pertussis outer membrane vesicles (OMVs) have appropriate specifications, making them a suitable vaccine candidate against pertussis. Materials and Methods: The OMVs were separated by a new serial ultra centrifugation technique. Transmission electron microscopy (TEM) examination, SDS-PAGE, Western blotting and ELISA assay were used to characterize the OMVs. Results: TEM studies showed the size of the extracted OMVs at 40-200 nm. The presence of pertussis toxin, filamentous hemagglutinin, and pertactin was verified using Western blot and ELISA assay. Conclusion: The presented technique is a simple and effective way to obtain OMVs from Bordetella pertussis. So it can be utilized as an appropriate procedure in the development of an OMV-based vaccine against pertussis.  


2020 ◽  
Vol 21 (5) ◽  
pp. 1674 ◽  
Author(s):  
Hasna Ahyayauch ◽  
Igor de la Arada ◽  
Massimo E. Masserini ◽  
José L. R. Arrondo ◽  
Félix M. Goñi ◽  
...  

The binding of Aβ42 peptide monomers to sphingomyelin/cholesterol (1:1 mol ratio) bilayers containing 5 mol% gangliosides (either GM1, or GT1b, or a mixture of brain gangliosides) has been assayed by density gradient ultracentrifugation. This procedure provides a direct method for measuring vesicle-bound peptides after non-bound fraction separation. This centrifugation technique has rarely been used in this context previously. The results show that gangliosides increase by about two-fold the amount of Aβ42 bound to sphingomyelin/cholesterol vesicles. Complementary studies of the same systems using thioflavin T fluorescence, Langmuir monolayers or infrared spectroscopy confirm the ganglioside-dependent increased binding. Furthermore these studies reveal that gangliosides facilitate the aggregation of Aβ42 giving rise to more extended β-sheets. Thus, gangliosides have both a quantitative and a qualitative effect on the binding of Aβ42 to sphingomyelin/cholesterol bilayers.


2019 ◽  
Vol 3 (2) ◽  
pp. 77
Author(s):  
Dhimar Maulud Dyahningrum ◽  
Mufasirin Mufasirin ◽  
Nenny Harijani ◽  
Poedji Hastutiek ◽  
Setiawan Koesdarto ◽  
...  

The aim of this research is to detect the presence of blood parasite that infects sacrificial cattle slaughtered during idul adha 1438 H in Surabaya City and Sidoarjo Regency. This research used 147 blood samples of sacrificial cattle and used two methods, those are thin blood smear stained with Giemsa 20% and Microhematocrit Centrifugation Technique. Based on the result of the examination using a microscope with 1000x magnification, there are positive samples infected with blood parasite, that consist of Babesia sp., and Anaplasma sp.


2019 ◽  
Vol 86 (1) ◽  
Author(s):  
Tahani S. Behour ◽  
Shawky M. Aboelhadid ◽  
Wahid M. Mousa ◽  
Adel S. Amin ◽  
Saeed A. El-Ashram

Trypanosoma evansi is enzootic in camels in Egypt, and water buffaloes act as a reservoir for camel infection. Molecular techniques have contributed towards understanding the epidemiology of T. evansi. Trypanosoma evansi was detected in acute and chronic stages of the disease in male and female mice by polymerase chain reaction (PCR) using two primers. Two experiments were conducted. In experiment I, two groups consisting of 26 female and 26 male mice received 104 trypanosome by I/P inoculation for each mouse. In experiment II, 42 female and 42 male mice were inoculated I/P with 102 trypanosome/mouse. In addition, five mice were kept as uninfected control for each group. Mice were monitored daily for parasitaemia level during the pre-patent period using the micro-haematocrit centrifugation technique (MHCT) and conventional PCR. The primer pairs, (Trypanosoma brucei) TBR1/2 and TeRoTat1.2 (T. evansi Rode Trypanozoon antigen type [RoTat] 1.2), detected the infection after 24 hours earlier than MHCT in both experiments. The course of infection that was detected by MHCT revealed three waves of parasitaemia in female mice and two waves in male mice in the chronic stage of infection. In addition, PCR was able to detect T. evansi in different organs in the chronic stage (i.e. disappearance of parasite from blood). Application of the two primer sets on blood samples from camels showed that all samples were positive by TBR1/2 primers and only 32 of 44 were positive by TeRoTat1.2 primers. Acutely and chronically Trypanosoma-infected mice were detected by PCR in blood and organs. TBR1/2 primers were more sensitive than TeRoTat1.2 primers in detecting Trypanosoma-infected mice, and more reliable in detecting field-infected camels and excluding carrier animals.


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