Effect of sperm DNA fragmentation on blastocyst formation rate and subsequent IVF outcome

Background: Male infertility associated with sperm DNA alteration has raised a new issue in assisted reproduction techniques (ARTs).Methods: It was a retrospective analytical study on 250 cases of routine IVF/ICSI performed at Swagat ART Centre from January 2017 to January 2020. We divided the patient according to the sperm DNA fragmentation index (DFI) as normal DFI≤15%, n=95, a moderate DFI≤30%, n=89, and a high DFI group >30%, n=66. Oocytes of each patient were almost equally divided and fertilization method was adopted as half IVF half ICSI or only ICSI in poor quality (oligo, astheno, teratozoospermia or with two or all three defect and compared the fertilization, cleavage, embryo formation, blastocyst formation, pregnancy and early embryo formation rate among these six groups. Results: Fertilization, cleavage, embryo formation, and clinical pregnancy rates were reported as higher in ≤15% DFI group of both IVF and ICSI-ET (87.3±26.2, 77.7±26.1, 68.2±28.8, 50.8 in IVF and 78.3±17.8, 70.3±31.2, 67.2±28.8, 57.6 respectively). Significant differences (p<0.01) are observed among all six groups. Higher abortion rate is observed in high DFI group of both IVF and ICSI.Conclusions: High sperm DFI causes low blastocyst formation and pregnancy outcome. Higher abortion rate observed in high DFI group indicated need of further study.

Two Agrobacterium-mediated Transformation Protocols of White Clover (Trifolium Repens) Through the Callus System

White clover (Trifolium repens) is one of the most widely cultivated livestock forage legumes co-cultivated worldwide with pasture grass in a mixed-sward setting, however, its persistence and aesthetic quality are severely affected by abiotic stresses. In this study, regeneration of white clover plants was conducted through a callus system for 4-5 months with a regeneration frequency of 36-41%. Inoculating 4-day-old cotyledons into MS media fortified with 0.4 mg·L-1 6-BA and 2 mg·L-1 2,4-D significantly increased the callus formation rate. Roots and cotyledons were better induced, followed by hypocotyls, leaves, and petioles. The development of differentiated structures performed effectively on MS supplemented with 1 mg·L-1 6-BA and 0.1 mg·L-1 NAA. Further, we determined factors affecting the Agrobacterium tumefaciens-mediated transient transformation for root-derived callus and 4-day-old cotyledons. The parameters that facilitated transient transformation were: Agrobacterium suspension density of 0.5 (OD600), 20 mg·L-1 AS, and 4-days co-cultivation duration. Subsequently, we developed two transformation protocols: transformation after callus formation in root segments (Protocol A) and transformation before callus initiation in 4-day-old cotyledons (Protocol B). The transformation frequencies varied from 1.92% to 3.17% in Protocol A and from 2.76% to 3.47% in Protocol B. We offer the possibility to regenerate multiple transgenic white clover from a single genetic background. In addition to assistance in identification of functional genes associated with yield, resistance and aesthetic quality, our research will also contribute to successful genetic manipulation and genome editing in white clover.

Duality of Interactions Between TGF-β and TNF-α During Tumor Formation

The tumor microenvironment is essential for the formation and development of tumors. Cytokines in the microenvironment may affect the growth, metastasis and prognosis of tumors, and play different roles in different stages of tumors, of which transforming growth factor β (TGF-β) and tumor necrosis factor α (TNF-α) are critical. The two have synergistic and antagonistic effect on tumor regulation. The inhibition of TGF-β can promote the formation rate of tumor, while TGF-β can promote the malignancy of tumor. TNF-α was initially determined to be a natural immune serum mediator that can induce tumor hemorrhagic necrosis, it has a wide range of biological activities and can be used clinically as a target to immune diseases as well as tumors. However, there are few reports on the interaction between the two in the tumor microenvironment. This paper combs the biological effect of the two in different aspects of different tumors. We summarized the changes and clinical medication rules of the two in different tissue cells, hoping to provide a new idea for the clinical application of the two cytokines.

Sweep imaging with Fourier transform as a tool with MRI for evaluating the effect of teriparatide on cortical bone formation in an ovariectomized rat model

Background Teriparatide (TPTD) is a drug for osteoporosis that promotes bone formation and improves bone quality. However, the effects of TPTD on cortical bone are not well understood. Sweep imaging with Fourier transform (SWIFT) has been reported as a useful tool for evaluating bound water of cortical bone, but it has yet to be used to investigate the effects of TPTD on cortical bone. This study aimed to evaluate the consequences of the effect of TPTD on cortical bone formation using SWIFT. Methods Twelve-week-old female Sprague-Dawley rats (n = 36) were reared after ovariectomy to create a postmenopausal osteoporosis model. They were divided into two groups: the TPTD and non-TPTD groups. Rats were euthanized at 4, 12, and 24 weeks after initiating TPTD treatment. Tibial bones were evaluated using magnetic resonance imaging (MRI) and bone histomorphometry. In MRI, proton density-weighted imaging (PDWI) and SWIFT imaging were performed. The signal-to-noise ratio (SNR) was calculated for each method. The same area evaluated by MRI was then used to calculate the bone formation rate by bone histomorphometry. Measurements were compared using the Mann-Whitney U-test, and a P-value of < 0.05 was considered significant. Results PDWI-SNR was not significantly different between the two groups at any time point (P = 0.589, 0.394, and 0.394 at 4, 12, and 24 weeks, respectively). Contrarily, SWIFT-SNR was significantly higher in the TPTD group than in the non-TPTD group at 4 weeks after initiating treatment, but it was not significantly different at 12 and 24 weeks (P = 0.009, 0.937, and 0.818 at 4, 12, and 24 weeks, respectively). The bone formation rate assessed by histomorphometry was significantly higher in the TPTD group than in the non-TPTD group at all timepoints (P < 0.05, all weeks). In particular, at 4 weeks, the bone formation rate was markedly higher in the TPTD group than in the non-TPTD group (P = 0.028, 1.98 ± 0.33 vs. 0.09 ± 0.05 μm3/μm2/day). Conclusions SWIFT could detect increased signals of bound water, reflecting the effect of TPTD on the cortical bone. The signal detected by SWIFT reflects a marked increase in the cortical bone formation rate.

GASP XXXVIII: The LOFAR-MeerKAT-VLA View on the Nonthermal Side of a Jellyfish Galaxy

Ram pressure stripping is a crucial evolutionary driver for cluster galaxies. It is thought to be able to accelerate the evolution of their star formation, trigger the activity of their central active galactic nucleus (AGN) and the interplay between galactic and environmental gas, and eventually dissipate their gas reservoirs. We explored the outcomes of ram pressure stripping by studying the nonthermal radio emission of the jellyfish galaxy JW100 in the cluster A2626 (z = 0.055), by combining LOw Frequency Array, MeerKAT, and Very Large Array observations from 0.144 to 5.5 GHz. We studied the integrated spectra of the stellar disk, the stripped tail, and the AGN; mapped the spectral index over the galaxy; and constrained the magnetic field intensity to between 11 and 18 μG in the disk and <10 μG in the tail. The stellar disk radio emission is dominated by a radiatively old plasma, likely related to an older phase of a high star formation rate. This suggests that the star formation was quickly quenched by a factor of 4 in a few 107 yr. The radio emission in the tail is consistent with the stripping scenario, where the radio plasma that originally accelerated in the disk is subsequently displaced in the tail. The morphology of the radio and X-ray emissions supports the scenario of the accretion of magnetized environmental plasma onto the galaxy. The AGN nonthermal spectrum indicates that relativistic electron acceleration may have occurred simultaneously with a central ionized gas outflow, thus suggesting a physical connection between the two processes.

Driving Galactic Outflows with Magnetic Fields at Low and High Redshift

Although galactic outflows play a key role in our understanding of the evolution of galaxies, the exact mechanism by which galactic outflows are driven is still far from being understood and, therefore, our understanding of associated feedback mechanisms that control the evolution of galaxies is still plagued by many enigmas. In this work, we present a simple toy model that can provide insight on how non-axisymmetric instabilities in galaxies (bars, spiral arms, warps) can lead to local exponential magnetic field growth by radial flows beyond the equipartition value by at least two orders of magnitude on a timescale of a few 100 Myr. Our predictions show that the process can lead to galactic outflows in barred spiral galaxies with a mass-loading factor η ≈ 0.1, in agreement with our numerical simulations. Moreover, our outflow mechanism could contribute to an understanding of the large fraction of barred spiral galaxies that show signs of galactic outflows in the chang-es survey. Extending our model shows the importance of such processes in high-redshift galaxies by assuming equipartition between magnetic energy and turbulent energy. Simple estimates for the star formation rate in our model together with cross correlated masses from the star-forming main sequence at redshifts z ∼ 2 allow us to estimate the outflow rate and mass-loading factors by non-axisymmetric instabilities and a subsequent radial inflow dynamo, giving mass-loading factors of η ≈ 0.1 for galaxies in the range of M ⋆ = 109–1012 M ⊙, in good agreement with recent results of sinfoni and kmos 3D.

Search for Hα Emitters at z ∼ 7.8: A Constraint on the Hα-based Star Formation Rate Density

We search for Hα emitters at z ∼ 7.8 in four gravitationally lensed fields observed in the Hubble Frontier Fields program. We use the Lyman break method to select galaxies at the target redshift and perform photometry in the Spitzer/IRAC 5.8 μm band to detect Hα emission from the candidate galaxies. We find no significant detections of counterparts in the IRAC 5.8 μm band, and this gives a constraint on the Hα luminosity function (LF) at z ∼ 7.8. We compare the constraint with previous studies based on rest-frame UV and far-infrared observations using the correlation between the Hα luminosity and the star formation rate. Additionally, we convert the constraint on the Hα LF into an upper limit for the star formation rate density (SFRD) at this epoch assuming the shape of the LF. We examine two types of parameterization of the LF and obtain an upper limit for the SFRD of log 10 ( ρ SFR [ M ⊙ yr − 1 Mpc − 3 ] ) ≲ − 1.1 at z ∼ 7.8. With this constraint on the SFRD, we present an independent probe into the total star formation activity including dust-obscured and unobscured star formation at the Epoch of Reionization.

The Environmental Dependence of Gas Properties in Dense Cores of a Protocluster at z ∼ 2.5 Revealed with ALMA

In a protocluster USS1558-003 at z = 2.53, galaxies in the dense cores show systematically elevated star-forming activity compared to those in less dense regions. To understand its origin, we look into the gas properties of the galaxies in the dense cores by conducting deep 1.1 mm observations with the Atacama Large Millimeter/submillimeter Array. We detect interstellar dust continuum emission from 12 member galaxies and estimate their molecular gas masses. Comparing these gas masses with our previous measurements from the CO(3–2) line, we infer that the latter might be overestimated. We find that the gas to stellar mass ratios of the galaxies in the dense cores tend to be higher (at M * ∼ 1010 M ⊙ where we see the enhanced star-forming activity), suggesting that such large gas masses can sustain their high star-forming activity. However, if we compare the gas properties of these protocluster galaxies with the gas scaling relations constructed for field galaxies at a similar cosmic epoch, we find no significant environmental difference at the same stellar mass and star formation rate. Although both gas mass ratios and star-forming activity are enhanced in the majority of member galaxies, they appear to follow the same scaling relation as field galaxies. Our results are consistent with the scenario in which the cold gas is efficiently supplied to protocluster cores and to galaxies therein along surrounding filamentary structures, which leads to the high gas mass fractions and thus the elevated star formation activity, but without changing the star formation law.

COLDz: Probing Cosmic Star Formation With Radio Free–Free Emission

Radio free–free emission is considered to be one of the most reliable tracers of star formation in galaxies. However, as it constitutes the faintest part of the radio spectrum—being roughly an order of magnitude less luminous than radio synchrotron emission at the GHz frequencies typically targeted in radio surveys—the usage of free–free emission as a star formation rate tracer has mostly remained limited to the local universe. Here, we perform a multifrequency radio stacking analysis using deep Karl G. Jansky Very Large Array observations at 1.4, 3, 5, 10, and 34 GHz in the COSMOS and GOODS-North fields to probe free–free emission in typical galaxies at the peak of cosmic star formation. We find that z ∼ 0.5–3 star-forming galaxies exhibit radio emission at rest-frame frequencies of ∼65–90 GHz that is ∼1.5–2 times fainter than would be expected from a simple combination of free–free and synchrotron emission, as in the prototypical starburst galaxy M82. We interpret this as a deficit in high-frequency synchrotron emission, while the level of free–free emission is as expected from M82. We additionally provide the first constraints on the cosmic star formation history using free–free emission at 0.5 ≲ z ≲ 3, which are in good agreement with more established tracers at high redshift. In the future, deep multifrequency radio surveys will be crucial in order to accurately determine the shape of the radio spectrum of faint star-forming galaxies, and to further establish radio free–free emission as a tracer of high-redshift star formation.