[Effects of exosomes from hepatocyte growth factor-modified human adipose mesenchymal stem cells on full-thickness skin defect in diabetic mice]

Objective: To investigate the effects and mechanism of exosomes from hepatocyte growth factor (HGF)-modified human adipose mesenchymal stem cells (ADSCs) on full-thickness skin defect wounds in diabetic mice. Methods: The experimental study method was adopted. Discarded adipose tissue of 3 healthy females (10-25 years old) who underwent abdominal surgery in the Department of Plastic Surgery of First Affiliated Hospital of Air Force Medical University from February to May 2021 was collected, and primary ADSCs were obtained by collagenase digestion method and cultured for 7 days. Cell morphology was observed by inverted phase contrast microscope. The ADSCs of third passage were transfected with HGF lentivirus and cultured for 5 days, and then the fluorescence of cells was observed by imaging system and the transfection rate was calculated. The exosomes of ADSCs of the third to sixth passages and the HGF transfected ADSCs of the third to sixth passages were extracted by density gradient centrifugation, respectively, and named, ADSC exosomes and HGF-ADSC exosomes. The microscopic morphology of exosomes was observed by transmission electron microscopy, and the positive expressions of CD9, CD63, and CD81 of exosomes were detected by flow cytometry, respectively. Twenty-four 6-week-old male Kunming mice were selected to make the diabetic models, and full-thickness skin defect wounds were made on the backs of mice. According to the random number table method, the mice were divided into phosphate buffer solution (PBS) group, HGF alone group, ADSC exosome alone group, and HGF-ADSC exosome group, with 6 mice in each group, and treated accordingly. On post injury day (PID) 3, 7, 10, and 14, the wounds were observed and the wound healing rate was calculated; the blood flow intensity of wound base was detected by Doppler flowmeter and the ratio of relative blood flow intensity on PID 10 was calculated. On PID 10, the number of Ki67 positive cells in wounds was detected by immunofluorescence method, and the number of new-vascularity of CD31 positive staining and tubular neovascularization in the wounds was detected by immunohistochemistry method; the protein expressions of protein endothelial nitric oxide synthase (eNOS), phosphatidylinositol 3-kinase (PI3K), phosphorylated PI3K (p-PI3K), protein kinase B (Akt) and phosphorylated Akt (p-Akt) in wounds were detected by Western blotting, and the ratios of p-PI3K to PI3K and p-Akt to Akt were calculated. On PID 14, the defect length and collagen regeneration of wound skin tissue were detected by hematoxylin and eosin staining and Masson staining, respectively, and the collagen volume fraction (CVF) was calculated. The number of samples is 3 in all cases. Data were statistically analyzed with repeated measurement analysis of variance, one-way analysis of variance, and Tukey test. Results: After 7 days of culture, the primary ADSCs were spindle shaped and arranged in vortex shape after dense growth. After 5 days of culture, HGF transfected ADSCs of the third passage carried green fluorescence, and the transfection rate was 85%. The ADSC exosomes and HGF-ADSC exosomes were similar in microscopic morphology, showing vesicular structures with an average particle size of 103 nm and 98 nm respectively, and both were CD9, CD63, and CD81 positive. On PID 3, the wounds of mice in the 4 groups were all red and swollen, with a small amount of exudate. On PID 7, the wounds of HGF-ADSC exosome group were gradually reduced, while the wounds of the other three groups were not significantly reduced. On PID 10, the wounds in the 4 groups were all reduced and scabbed. On PID 14, the wounds in HGF-ADSC exosome group were basically healed, while the residual wounds were found in the other three groups. On PID 3, the healing rates of wounds in the four groups were similar (P>0.05); On PID 7 and 10, the wound healing rates in HGF-ADSC exosome group were significantly higher than those in PBS group, HGF alone group, and ADSC exosome alone group, respectively (with q values of 13.11, 13.11, 11.89, 12.85, 11.28, and 7.74, respectively, all P<0.01); on PID 14, the wound healing rate in HGF-ADSC exosome group was significantly higher than that in PBS group, HGF alone group, and ADSC exosome alone group (with q values of 15.50, 11.64, and 6.36, respectively, all P<0.01). On PID 3, there was no obvious blood supply in wound base of mice in the 4 groups. On PID 7, microvessels began to form in the wound base of HGF-ADSC exosome group, while the wound base of the other three groups was only congested at the wound edge. On PID 10, microvessel formation in wound base was observed in the other 3 groups except in PBS group, which had no obvious blood supply. On PID 14, the blood flow intensity of wound base in HGF-ADSC exosome group was stronger than that in the other 3 groups, and the distribution was uniform. On PID 10, the ratio of wound base relative blood flow intensity in HGF-ADSC exosome group was significantly higher than that in PBS group, HGF alone group, and ADSC exosome alone group (with q values of 23.73, 19.32, and 9.48, respectively, all P<0.01); The numbers of Ki67-positive cells and new-vascularity of wounds in HGF-ADSC exosome group were significantly higher than those in PBS group, HGF alone group, and ADSC exosome alone group, respectively (with q values of 19.58, 18.20, 11.04, 20.68, 13.79, and 8.12, respectively, P<0.01). On PID 10, the protein expression level of eNOS of wounds in HGF-ADSC exosome group was higher than that in PBS group, HGF alone group, and ADSC exosome alone group (with q values of 53.23, 42.54, and 26.54, respectively, all P<0.01); the ratio of p-PI3K to PI3K and the ratio of p-Akt to Akt of wounds in HGF-ADSC exosome group were significantly higher than those in PBS group, HGF alone group, and ADSC exosome alone group, respectively (with q values of 16.11, 11.78, 6.08, 65.54, 31.63, and 37.86, respectively, P<0.01). On PID 14, the length of skin tissue defect in the wounds of HGF-ADSC exosome group was shorter than that in PBS group, HGF alone group, and ADSC exosome alone group (with q values of 20.51, 18.50, and 11.99, respectively, all P<0.01); the CVF of wounds in HGF-ADSC exosome group was significantly higher than that in PBS group, HGF alone group and ADSC exosome alone group (with q values of 31.31, 28.52, and 12.35, respectively, all P<0.01). Conclusions: Human HGF-ADSC exosomes can significantly promote wound healing in diabetic mice by increasing neovascularization in wound tissue, and the mechanism may be related to the increased expression of eNOS in wounds by activating PI3K/Akt signaling pathway.

[Regulatory effects of bio-intensity electric field on microtubule acetylation in human epidermal cell line HaCaT]

Objective: To investigate the regulatory effects of bio-intensity electric field on directional migration and microtubule acetylation in human epidermal cell line HaCaT, aiming to provide molecular theoretical basis for the clinical treatment of wound repair. Methods: The experimental research methods were used. HaCaT cells were collected and divided into simulated electric field group (n=54) placed in the electric field device without electricity for 3 h and electric field treatment group (n=52) treated with 200 mV/mm electric field for 3 h (the same treatment methods below). The cell movement direction was observed in the living cell workstation and the movement velocity, trajectory velocity, and direction of cosθ of cell movement within 3 h of treatment were calculated. HaCaT cells were divided into simulated electric field group and electric field treatment 1 h group, electric field treatment 2 h group, and electric field treatment 3 h group which were treated with 200 mV/mm electric field for corresponding time. HaCaT cells were divided into simulated electric field group and 100 mV/mm electric field group, 200 mV/mm electric field group, and 300 mV/mm electric field group treated with electric field of corresponding intensities for 3 h. The protein expression of acetylated α-tubulin was detected by Western blotting (n=3). HaCaT cells were divided into simulated electric field group and electric field treatment group, and the protein expression of acetylated α-tubulin was detected and located by immunofluorescence method (n=3). Data were statistically analyzed with Kruskal-Wallis H test,Mann-Whitney U test, Bonferroni correction, one-way analysis of variance, least significant difference test, and independent sample t test. Results: Within 3 h of treatment, compared with that in simulated electric field group, the cells in electric field treatment group had obvious tendency to move directionally, the movement velocity and trajectory velocity were increased significantly (with Z values of -8.53 and -2.05, respectively, P<0.05 or P<0.01), and the directionality was significantly enhanced (Z=-8.65, P<0.01). Compared with (0.80±0.14) in simulated electric field group, the protein expressions of acetylated α-tubulin in electric field treatment 1 h group (1.50±0.08) and electric field treatment 2 h group (1.89±0.06) were not changed obviously (P>0.05), while the protein expression of acetylated α-tubulin of cells in electric field treatment 3 h group (3.37±0.36) was increased significantly (Z=-3.06, P<0.05). After treatment for 3 h, the protein expressions of acetylated α-tubulin of cells in 100 mV/mm electric field group, 200 mV/mm electric field group, and 300 mV/mm electric field group were 1.63±0.05, 2.24±0.08, and 2.00±0.13, respectively, which were significantly more than 0.95±0.27 in simulated electric field group (P<0.01). Compared with that in 100 mV/mm electric field group, the protein expressions of acetylated α-tubulin in 200 mV/mm electric field group and 300 mV/mm electric field group were increased significantly (P<0.01); the protein expression of acetylated α-tubulin of cells in 300 mV/mm electric field group was significantly lower than that in 200 mV/mm electric field group (P<0.05). After treatment for 3 h, compared with that in simulated electric field group, the acetylated α-tubulin of cells had enhanced directional distribution and higher protein expression (t=5.78, P<0.01). Conclusions: Bio-intensity electric field can induce the directional migration of HaCaT cells and obviously up-regulate the level of α-ubulin acetylation after treatment at 200 mV/mm bio-intensity electric field for 3 h.

A, Barbano A, Barwick SW, Bastian B, Basu V, Baur S, Bay R, Beatty JJ, Becker KH, Becker Tjus J, Bellenghi C, BenZvi S, Berley D, Bernardini E, Besson DZ, Binder G, Bindig D, Blaufuss E, Blot S, Boddenberg M, Bontempo F, Borowka J, Böser S, Botner O, Böttcher J, Bourbeau E, Bradascio F, Braun J, Brinson B, Bron S, Brostean-Kaiser J, Browne S, Burgman A, Burley RT, Busse RS, Campana MA, Carnie-Bronca EG, Chen C, Chen Z, Chirkin D, Choi K, Clark BA, Clark K, Classen L, Coleman A, Collin GH, Conrad JM, Coppin P, Correa P, Cowen DF, Cross R, Dappen C, Dave P, De Clercq C, DeLaunay JJ, Delgado López D, Dembinski H, Deoskar K, Desai A, Desiati P, de Vries KD, de Wasseige G, de With M, DeYoung T, Diaz A, Díaz-Vélez JC, Dittmer M, Dujmovic H, Dunkman M, DuVernois MA, Dvorak E, Ehrhardt T, Eller P, Engel R, Erpenbeck H, Evans J, Evenson PA, Fan KL, Fazely AR, Fedynitch A, Feigl N, Fiedlschuster S, Fienberg AT, Filimonov K, Finley C, Fischer L, Fox D, Franckowiak A, Friedman E, Fritz A, Fürst P, Gaisser TK, Gallagher J, Ganster E, Garcia A, Garrappa S, Gerhardt L, Ghadimi A, Glaser C, Glauch T, Glüsenkamp T, Goldschmidt A, Gonzalez JG, Goswami S, Grant D, Grégoire T, Griswold S, Günther C, Gutjahr P, Haack C, Hallgren A, Halliday R, Halve L, Halzen F, Ha Minh M, Hanson K, Hardin J, Harnisch AA, Haungs A, Hebecker D, Helbing K, Henningsen F, Hettinger EC, Hickford S, Hignight J, Hill C, Hill GC, Hoffman KD, Hoffmann R, Hokanson-Fasig B, Hoshina K, Huang F, Huber M, Huber T, Hultqvist K, Hünnefeld M, Hussain R, Hymon K, In S, Iovine N, Ishihara A, Jansson M, Japaridze GS, Jeong M, Jin M, Jones BJP, Kang D, Kang W, Kang X, Kappes A, Kappesser D, Kardum L, Karg T, Karl M, Karle A, Katz U, Kauer M, Kellermann M, Kelley JL, Kheirandish A, Kin K, Kintscher T, Kiryluk J, Klein SR, Koirala R, Kolanoski H, Kontrimas T, Köpke L, Kopper C, Kopper S, Koskinen DJ, Koundal P, Kovacevich M, Kowalski M, Kozynets T, Kun E, Kurahashi N, Lad N, Lagunas Gualda C, Lanfranchi JL, Larson MJ, Lauber F, Lazar JP, Lee JW, Leonard K, Leszczyńska A, Li Y, Lincetto M, Liu QR, Liubarska M, Lohfink E, Lozano Mariscal CJ, Lu L, Lucarelli F, Ludwig A, Luszczak W, Lyu Y, Ma WY, Madsen J, Mahn KBM, Makino Y, Mancina S, Mariş IC, Martinez-Soler I, Maruyama R, Mase K, McElroy T, McNally F, Mead JV, Meagher K, Mechbal S, Medina A, Meier M, Meighen-Berger S, Micallef J, Mockler D, Montaruli T, Moore RW, Morse R, Moulai M, Naab R, Nagai R, Nahnhauer R, Naumann U, Necker J, Nguyen LV, Niederhausen H, Nisa MU, Nowicki SC, Nygren D, Obertacke Pollmann A, Oehler M, Oeyen B, Olivas A, O’Sullivan E, Pandya H, Pankova DV, Park N, Parker GK, Paudel EN, Paul L, Pérez de los Heros C, Peters L, Peterson J, Philippen S, Pieper S, Pittermann M, Pizzuto A, Plum M, Popovych Y, Porcelli A, Prado Rodriguez M, Price PB, Pries B, Przybylski GT, Raab C, Rack-Helleis J, Raissi A, Rameez M, Rawlins K, Rea IC, Rehman A, Reichherzer P, Reimann R, Renzi G, Resconi E, Reusch S, Rhode W, Richman M, Riedel B, Roberts EJ, Robertson S, Roellinghoff G, Rongen M, Rott C, Ruhe T, Ryckbosch D, Rysewyk Cantu D, Safa I, Saffer J, Sanchez Herrera SE, Sandrock A, Sandroos J, Santander M, Sarkar S, Sarkar S, Satalecka K, Schaufel M, Schieler H, Schindler S, Schmidt T, Schneider A, Schneider J, Schröder FG, Schumacher L, Schwefer G, Sclafani S, Seckel D, Seunarine S, Sharma A, Shefali S, Silva M, Skrzypek B, Smithers B, Snihur R, Soedingrekso J, Soldin D, Spannfellner C, Spiczak GM, Spiering C, Stachurska J, Stamatikos M, Stanev T, Stein R, Stettner J, Steuer A, Stezelberger T, Stokstad R, Stürwald T, Stuttard T, Sullivan GW, Taboada I, Ter-Antonyan S, Tilav S, Tischbein F, Tollefson K, Tönnis C, Toscano S, Tosi D, Trettin A, Tselengidou M, Tung CF, Turcati A, Turcotte R, Turley CF, Twagirayezu JP, Ty B, Unland Elorrieta MA, Valtonen-Mattila N, Vandenbroucke J, van Eijndhoven N, Vannerom D, van Santen J, Verpoest S, Walck C, Watson TB, Weaver C, Weigel P, Weindl A, Weiss MJ, Weldert J, Wendt C, Werthebach J, Weyrauch M, Whitehorn N, Wiebusch CH, Williams DR, Wolf M, Woschnagg K, Wrede G, Wulff J, Xu XW, Yanez JP, Yoshida S, Yu S, Yuan T, Zhang Z, Zhelnin P. Evidence for neutrino emission from the nearby active galaxy NGC 1068

A supermassive black hole, obscured by cosmic dust, powers the nearby active galaxy NGC 1068. Neutrinos, which rarely interact with matter, could provide information on the galaxy’s active core. We searched for neutrino emission from astrophysical objects using data recorded with the IceCube neutrino detector between 2011 and 2020. The positions of 110 known gamma-ray sources were individually searched for neutrino detections above atmospheric and cosmic backgrounds. We found that NGC 1068 has an excess of 79 − 20 + 22 neutrinos at tera–electron volt energies, with a global significance of 4.2σ, which we interpret as associated with the active galaxy. The flux of high-energy neutrinos that we measured from NGC 1068 is more than an order of magnitude higher than the upper limit on emissions of tera–electron volt gamma rays from this source.

Portable diagnostic package for Thomson scattering and optical emission spectroscopy on Princeton field-reversed configuration 2 (PFRC 2)

An Advanced Research Projects Agency-Energy funded diagnostic system has been deployed to the Princeton field-reversed configuration 2 (PFRC-2) device, located at Princeton Plasma Physics Laboratory. The Portable Diagnostic Package (PDP), designed at Oak Ridge National Laboratory, allows for the measurement of Thomson Scattering (TS) for electron density and temperature and Optical Emission Spectroscopy (OES) for ion temperature, impurity density, and ion velocity. A tunable spectrometer on the PDP with three gratings provides the flexibility to measure low (1 eV) and high (1000 eV) electron temperature ranges from TS. Additionally, using a second spectrometer, the OES diagnostic can survey light emission from various ion excitation levels for wide wavelength ranges. The electron density (<2 × 10¹⁹ m^-3) of plasmas generated in PFRC-2 has been below the PDP TS discrimination threshold, which has made TS signal detection challenging against a high-background of laser stray light. The laser stray light was iteratively reduced by making modifications to the entrance and exit geometry on PFRC-2. Rayleigh scattering experiments on PFRC have yielded the TS discrimination sensitivity to be >1 × 10²⁰ m^-3 for the PDP. A recently implemented narrow-band notch spectral filter that masks the second harmonic 532 nm Nd:YAG laser wavelength has increased the system's TS light discrimination sensitivity 65 times compared to the instance when the notch filter was not implemented. The hardware implementation including design changes to the flight tubes and Brewster windows will be discussed, along with results from Rayleigh and rotational Raman scattering sensitivity analyses, which were used to establish a quantitative figure of merit on the system performance. The Raman scattering calibration with the notch filter has improved the PDP electron density threshold to 1 ± 0.5 × 10¹⁸ m^-3.

Implementation of a portable diagnostic system for Thomson scattering measurements on an electrothermal arc source

To fulfill the increasing needs of diagnostic support for researchers in plasma technology, a portable diagnostic package (PDP) equipped for both laser Thomson scattering (TS) and optical emission spectroscopy has been designed and constructed at Oak Ridge National Laboratory (ORNL), aiming to measure the temperature and number density of electrons and temperatures of ions in plasma devices. The PDP has been initially implemented on a high density and low temperature electrothermal arc source (ET-arc) at ORNL to test its TS capability. TS from the plasmas in the ET-arc has been obtained using the PDP. The electron temperature and number density were determined from TS spectra. These results were then compared to measurements from previous studies on the ET-arc. The TS diagnostic measured 0.8 ± 0.1, 1.3 ± 0.2, and 0.7 ± 0.1 eV and (4.4 ± 0.5) × 10²¹, (5.9 ± 0.7) × 10²¹, and (4.3 ± 0.5) x 10²¹ m^-3, respectively, from three lines of sight that transect the plasma column.

Ultralight type I transvaginal mesh: an alternative for recurrent severe posterior vaginal prolapse

OBJECTIVE

This study aimed to analyze the medium-term outcomes of ultralight type I mesh for postmenopausal women with recurrent severe posterior vaginal prolapse (PVP).

METHODS

All participants underwent transvaginal ultralight type I mesh repair between April 2016 and April 2021 and were followed until May 2022. Pelvic Organ Prolapse Quantification System (POP-Q) staging, mesh-related complications, Patient Global Impression of Improvement (PGI-I) scale and quality of life questionnaire responses were evaluated. The primary outcome was composite surgical success rate at the last follow-up, composite success being defined as no vaginal bulge symptoms, no POP-Q point at or beyond the hymen and no re-treatment for POP. Secondary outcomes included anatomic outcomes (POP-Q score), symptomatic relief and complications.

RESULTS

The median follow-up was 37.3 months. At the last follow-up, the composite success rate was 75%, and POP-Q scores for the vault and posterior wall and quality of life questionnaire scores were significantly improved (p < 0.01). The subjective satisfaction (PGI-I ≤ 2) rate was 83.3%. There were no mesh-related complications.

CONCLUSIONS

Ultralight mesh can achieve good clinical outcomes and substantially improve the quality of life of patients with severe recurrent PVP in the medium term, and may thus be a viable alternative for treating this condition.

Search for Unstable Sterile Neutrinos with the IceCube Neutrino Observatory

We present a search for an unstable sterile neutrino by looking for a resonant signal in eight years of atmospheric ν_{μ} data collected from 2011 to 2019 at the IceCube Neutrino Observatory. Both the (stable) three-neutrino and the 3+1 sterile neutrino models are disfavored relative to the unstable sterile neutrino model, though with p values of 2.8% and 0.81%, respectively, we do not observe evidence for 3+1 neutrinos with neutrino decay. The best-fit parameters for the sterile neutrino with decay model from this study are Δm_{41}^{2}=6.7_{-2.5}^{+3.9}  eV^{2}, sin^{2}2θ_{24}=0.33_{-0.17}^{+0.20}, and g^{2}=2.5π±1.5π, where g is the decay-mediating coupling. The preferred regions of the 3+1+decay model from short-baseline oscillation searches are excluded at 90% C.L.

[Recent progress of aptasensors for tumor exosome-associated protein detection]

Exosomes are phospholipid bilayer membrane-enclosed vesicles released from cells with diameters of 30-150 nm, exosomes can directly reflect the physiological and functional state of secretory cells, participate in material transport and information communication between cells, which are of great significance as biomarkers for early tumor diagnosis and treatment evaluation. There are many detection methods for exosomes, among which aptasensor technology with the properties of low price and easy operation, fast response, high sensitivity, remarkable specificity helps tumor patients to find, diagnose and treat early, improve the survival rate, and provide important basis for the evaluation of the prognosis. There are seven types of common aptasensors: fluorescent, electrochemical, colorimetric, luminescence, lateral flow strips, surface-enhanced Raman scattering and surface plasmon resonance sensors. Different aptasensors have different characteristics, this article focuses on the research progress of several common aptasensor for tumor exosomes detection.

Logistic regression analysis of risk factors for intra-abdominal hypertension after giant ventral hernia repair: a retrospective cohort study

BACKGROUND

Intra-abdominal hypertension (IAH) is a classical complication after giant ventral hernia surgery and may lead to abdominal compartment syndrome (ACS). Assessment of risk factors and prevention of IAH/ACS are essential for hernia surgeons.

METHODS

We performed a retrospective study including 58 giant ventral hernia patients in our center between Jan 1, 2017, and Mar 1, 2022, we recorded age, gender, chronic obstructive pulmonary disease (COPD), coronary heart disease (CHD), hypertension, type 2 diabetes mellitus (T2DM), hypoproteinemia, body mass index (BMI), the ratio of hernia sac volume to abdominal cavity volume (HSV/ACV), defect width, tension reduction procedure (TRP), positive fluid balance (PFB) and IAH of these patients and analyzed the data using univariate and multivariate logistic regression to screen the risk factors for IAH after surgery.

RESULTS

The multivariate analysis showed that HSV/ACV ≥ 25%, hypoproteinemia, and PFB were independent risk factors for the occurrence of IAH after giant ventral hernia repair (P = 0.025, 0.016, 0.017, respectively). We did not find any correlation between postoperative IAH and the patient's age, gender, COPD, CHD, hypertension, T2DM, BMI, defect width, TRP, and PFB.

CONCLUSION

Identifying risk factors is of great significance for the early identification and prevention of IAH/ACS. We found that HSV/ACV ≥ 25%, hypoproteinemia, and PFB were independent risk factors for IAH after giant ventral hernia repair.

[The crucial toxic components of ambient fine particles promoted the maturation and differentiation of megakaryocytes]

Objective: To reveal the crucial toxic components of ambient fine particles (PM2.5) that affect the maturation and differentiation of megakaryocytes. Methods: Human megakaryocytes were exposed to the organic fractions, metallic fractions and water-soluble fractions of PM2.5 at two exposure doses (i.e. actual air proportion concentration or the same concentration), respectively. The cell viability was performed to screen the non-cytotoxic levels of toxic components of PM2.5 using the CCK-8 assay. CellTiter-Blue assay, morphological observation, flow cytometry analysis and WGA staining assay were used to evaluate the cell morphological changes, occurrence of DNA ploidy, alteration in the expressions of biomarkers and platelet formation, which were key indicators of the maturation and differentiation of megakaryocytes. Results: Compared to the control group, both metallic and organic components of PM2.5 resulted in a lag in megakaryocytes with an increase in cell volume and the onset of DNA ploidy. Flow cytometry analysis showed that CD33 (the marker of myeloid-specific) decreased and CD41a (a megakaryocyte maturation-associated antigen) increased in metallic and organic components of PM2.5 treatment groups. Moreover, compared to the control group, budding protrusions increased in metallic and organic components of PM2.5 treatment groups. The water-soluble components had no effect on the maturation and differentiation of macrophages. Conclusion: Metallic and organic components of PM2.5 are the crucial toxic components that promote the maturation and differentiation of megakaryocytes.

Self-compression of stimulated Raman backscattering by a flying focus

The regime of self-compression has been proposed for plasma-based backward Raman amplification upon a flying focus. By using a pumping focus moving with a speed equal to the group velocity of stimulated Raman backscattering (SRBS), only a short part of SRBS which always synchronizes with the flying focus can be amplified. Therefore, instead of a short pulse, plasma noise or a long pulse can seed the BRA amplifiers. Here we demonstrate the regime by 2D particle-in-cell simulations, showing that the pump pulse is compressed from 26 ps to 116 fs, with an output amplitude comparable with the case of a well-synchronized short seed. As only one laser pulse is used in the simulation, the results present a significant path to simplify the Raman amplifiers.

Pregnancy of cryopreserved ovine embryos at different developmental stages

BACKGROUND

Developmental stage and cryopreservation method have significant impact on the pregnancy rate after transfer of embryos produced in vivo.

OBJECTIVE

To determine the pregnancy outcomes from ovine embryos cryopreserved at different developmental stages.

MATERIALS AND METHODS

Embryos at different developmental stages were obtained from donor ewes through simultaneous estrus treatment and laparoscopic artificial insemination. Embryos, either cryopreserved via vitrification or slow freezing method, were implanted into recipient ewes. The pregnancy rate was determined 35 days after transfer.

RESULTS

The pregnancy rate of developing embryos increases after transfer from the morula stage, early blastocyst to expanded blastocyst stages (64.9%, 73.9% and 81.3%, respectively). However, cryopreservation significantly decreases the pregnancy rate of embryos at all three developmental stages, and there is no significant difference among developmental stages (43.9%, 43.7%, 52.9%, respectively). There is also no significant difference in the pregnancy rate between slowly-frozen embryos and vitrified embryos.

CONCLUSION

The pregnancy outcomes of embryo transfer is better at the expanded blastocyst stage than at earlier stages. However, no difference is observed in the pregnancy rate of embryos at different developmental stage after cryopreservation, either by slow freezing and vitrification. Cryopreservation methods for ovine embryos, both slow freezing and vitrification, need further improvement. doi.org/10.54680/fr22510110512.

Test of a multi-gigawatt, 800 ns high power microwave driver based on Marx generator and metal-oxide varistors

High power microwave (HPM) sources usually require a well-defined rectangular pulse waveform, which is especially true for the case of long pulse (>100 ns), stable, and high efficiency operation. Most long pulse HPM drivers are realized with pulse forming networks. This paper presents a long pulse driver composed of a conventional Marx generator and metal-oxide varistors (MOVs), utilizing the MOV's nonlinear V-I characteristic. This method is easy to implement, and it has an additional benefit that the voltage can be stabilized even if the load's impedance changes slightly. A low inductance zig-zag folding structure of the MOV is designed to decrease its size and self-inductance. An LC filter is used to reduce the energy loss in the MOV. In the experiment, a 400 kV, 800 ns long pulse is achieved at a foil-less electron diode, and longer than 300 ns HPM generation is obtained.

Evidence for Nonlinear Gluon Effects in QCD and Their Mass Number Dependence at STAR

The STAR Collaboration reports measurements of back-to-back azimuthal correlations of di-π^{0}s produced at forward pseudorapidities (2.6<η<4.0) in p+p, p+Al, and p+Au collisions at a center-of-mass energy of 200 GeV. We observe a clear suppression of the correlated yields of back-to-back π^{0} pairs in p+Al and p+Au collisions compared to the p+p data. The observed suppression of back-to-back pairs as a function of transverse momentum suggests nonlinear gluon dynamics arising at high parton densities. The larger suppression found in p+Au relative to p+Al collisions exhibits a dependence of the saturation scale Q_{s}^{2} on the mass number A. A linear scaling of the suppression with A^{1/3} is observed with a slope of -0.09±0.01.

Search for Higgs Boson Pair Production in the Four b Quark Final State in Proton-Proton Collisions at sqrt[s]=13 TeV

A search for pairs of Higgs bosons produced via gluon and vector boson fusion is presented, focusing on the four b quark final state. The data sample consists of proton-proton collisions at a center-of-mass energy of 13 TeV, collected with the CMS detector at the LHC, and corresponds to an integrated luminosity of 138  fb^{-1}. No deviation from the background-only hypothesis is observed. A 95% confidence level upper limit on the Higgs boson pair production cross section is observed at 3.9 times the standard model prediction for an expected value of 7.8. Constraints are also set on the modifiers of the Higgs field self-coupling, κ_{λ}, and of the coupling of two Higgs bosons to two vector bosons, κ_{2 V}. The observed (expected) allowed intervals at the 95% confidence level are -2.3<κ_{λ}<9.4 (-5.0<κ_{λ}<12.0) and -0.1<κ_{2 V}<2.2 (-0.4<κ_{2 V}<2.5). These are the most stringent observed constraints to date on the HH production cross section and on the κ_{2 V } coupling.

Observation of WWW Production in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector

This Letter reports the observation of WWW production and a measurement of its cross section using 139  fb^{-1} of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. Events with two same-sign leptons (electrons or muons) and at least two jets, as well as events with three charged leptons, are selected. A multivariate technique is then used to discriminate between signal and background events. Events from WWW production are observed with a significance of 8.0 standard deviations, where the expectation is 5.4 standard deviations. The inclusive WWW production cross section is measured to be 820±100 (stat)±80 (syst)  fb, approximately 2.6 standard deviations from the predicted cross section of 511±18  fb calculated at next-to-leading-order QCD and leading-order electroweak accuracy.

Comparison of outcomes of ventral hernia repair using different meshes: a systematic review and network meta-analysis

PURPOSE

We conducted a network meta-analysis to evaluate potential differences in patient outcomes when different meshes, especially biological meshes, were used for ventral hernia repair.

METHODS

PubMed, Embase, Cochrane Library, and Clinical Trials.gov databases were searched for studies comparing biological meshes with biological or synthetic meshes for ventral hernia repair. The outcomes were hernia recurrence rate, surgical site infection, and seroma. We performed a two-step network meta-analysis to investigate the outcomes of several biological meshes: non-cross-linked human acellular dermal matrix (NCHADM), non-cross-linked porcine ADM (NCPADM), non-cross-linked bovine ADM (NCBADM), cross-linked porcine ADM (CPADM), and porcine small intestinal submucosa (PSIS).

RESULTS

From 6304 publications, 23 studies involving 2603 patients were finally included. We found no differences between meshes in recurrence at 1-year follow-up and in surgical site infection rate. NCBADM was associated with the lowest recurrence rate and the lowest surgical site infection rate. NCHADM implantation was associated with the lowest rate of seroma. PSIS was associated with a higher risk of seroma than NCHADM (pooled risk ratio 3.89, 95% confidence interval 1.13-13.39) and NCPADM (RR 3.42, 95% CI 1.29-9.06).

CONCLUSIONS

Our network meta-analysis found no differences in recurrence rate or surgical site infection among different biological meshes. The incidence of postoperative seroma was higher with PSIS than with acellular dermal matrices. We observed large heterogeneity in the studies of ventral hernia repair using biological meshes, and, therefore, well-designed randomized clinical trials are needed.