Experimental demonstration on 400†nm-scale bandwidth optical parametric chirped-pulse amplification based on mixed cascaded crystals.

We present an optical parametric chirped-pulse amplification (OPCPA) based on mixed cascaded crystals, taking advantage of the unique parametric phase-matching of lithium triborate (LiB3O5, LBO) and yttrium calcium oxyborate ((YCa4O(BO3)3, YCOB) crystals. The OPCPA properties of LBO at 880 nm and YCOB at 750 nm are studied respectively. After amplification by two LBO and two YCOB crystals, a total signal gain of 108 and spectral bandwidth close to 400 nm is obtained. After accurate dispersion compensation with a grating-pair compressor and chirped mirror compensator, a pulse duration of 9.4 fs is obtained by a SHG-frequency-resolved optical grating (FROG). This approach will be of great significance in high energy amplifier for high peak power few-cycle laser sources.

Anion-Counterion Strategy toward Organic Cocrystal Engineering for Near-Infrared Photothermal Conversion and Solar-Driven Water Evaporation.

An anion-counterion strategy is proposed to construct organic mono-radical charge-transfer cocrystals for near-infrared photothermal conversion and solar-driven water evaporation. Ionic compounds with halogen anions as the counterions serve as electron donors, providing the necessary electrons for efficient charge transfer with unchanged skeleton atoms and structures as well as the broad red-shifted absorption (200-2000 nm) and unprecedented photothermal conversion efficiency (~90.5 %@808 nm) for the cocrystals. Based on these cocrystals, an excellent solar-driven interfacial water evaporation rate up to 6.1±1.1 kg ⋅ m-2 ⋅ h-1 under 1 sun is recorded due to the comprehensive evaporation effect from the cocrystal loading in polyurethane foams and chimney addition, such performance is superior to the reported results on charge-transfer cocrystals or other materials for solar-driven interfacial evaporation. This prototype exhibits the great potential of cocrystals prepared by the one-step mechanochemistry method in practical large-scale seawater desalination applications.

Etiologies and Mechanisms of Ischemic Stroke Associated with Sexual Intercourse: A Literature Review.

BACKGROUND: Exposure to some special events, also called stroke triggers, can precipitate the onset of ischemic stroke (IS). Previous studies have presented preliminary hypotheses about sexual intercourse as a trigger of IS in predisposed individuals, but the mechanisms of IS associated with sexual intercourse are still not well defined. This literature review summarizes the etiologies and mechanisms of IS associated with sexual intercourse. Further studies on stroke triggers are warranted, and early recognition and appropriate preventive strategies directed against the short-term risks posed by stroke triggers may complement the long-term risk factor reduction approach. METHODS: Articles were selected from PubMed (1946-2021) and Web of Science Core Collection (1990-2021) using the following search terms: ischemic stroke, ischaemic stroke, stroke, cerebral infarction, cerebral ischemia, cerebral embolism, embolism, sexual intercourse, sexual activity, intercourse, coitus, coition, and coital. RESULTS: A total of 20 studies, which included 26 patients with IS associated with sexual intercourse, were included. This literature review found that IS associated with sexual intercourse is not rare but has not received enough attention, and paradoxical embolization and postcoital arterial dissection are common etiologies. Other etiologies include drug usage (such as sexual adjuvant drugs and illicit drugs), paroxysmal sympathetic hyperactivity, and reversible cerebral vasoconstriction syndrome. DISCUSSION/CONCLUSION: Sexual intercourse should be considered an important trigger for IS. Clinicians should be aware that IS associated with sexual intercourse is not subjective but may be a warning sign of multiple etiologies and mechanisms.

Experimental demonstration of 1011 temporal contrast in pure nanosecond optical parametric chirped pulse amplifiers.

The temporal contrast of ultrashort and ultraintense laser pulses can significantly influence the laser-plasma interactions. As the optical parametric chirped pulse amplification (OPCPA) has been widely adopted in these laser facilities, the inherent optical parametric fluorescence, exhibiting a pedestal in the time window of the pump pulse, has become a significant problem. In this paper, we investigated experimentally its influence on the contrast of the compressed pulses at 808 nm using a multistage OPCPA amplifier. Compared to the highest value of 108 ever reported in the literature for such a type of regime, by adjusting the pump energy allocation between OPCPA stages and controlling the gain of small signal regime, we for the first time, to the best of our knowledge, realized a 1011 temporal contrast in a pure nanosecond OPCPA design at a gain exceeding 7×108, without adopting any other noise cleaning methods, such as picosecond OPCPA, cross-polarized wave generation, etc. This indicates that the OPCPA has a very significant potential for contrast improvement and to become a candidate for the future high-energy amplifiers in ultrashort high-power laser facilities.

Ultra-broadband high conversion efficiency optical parametric chirped-pulse amplification based on YCOB crystals.

We present a high efficiency and ultra-broadband optical parametric chirped-pulse amplification (OPCPA) system fully based on yttrium calcium oxyborate (YCOB) crystals. The OPCPA properties of YCOB at 808 nm are studied for both high gain and saturated amplification. The non-collinear angle is finely tuned to study the variation of gain spectrum at a certain phase-matching angle of YCOB crystals. After amplification by four YCOB crystals, a total signal gain of 0.9×109 is obtained and the FWHM spectral bandwidth is still over 100 nm. An amplified signal pulse of 182 mJ is achieved with pump energy of 440 mJ in the saturated amplification stage and the conversion efficiency is about 40%. After a four-grating compressor, a pulse duration of 20 fs is measured by a second-order autocorrelator.

Temporal contrast enhancement of ultrashort pulses using a spatiotemporal plasma-lens filter.

The spatiotemporal plasma-lens filter proposed here enhances the temporal contrast of the ultrashort pulse laser by combining plasma optics and spatial filtering. Experimentally, the spatiotemporal plasma-lens filter has improved the temporal contrast by 2 orders of magnitude with 80% laser transmission efficiency under a 1 Hz repetitive laser operation. Not only were the pre-pulse and the pedestal cleaned out, but also the rising edge of the main pulse was sharpened.

Aerobic biodegradation of p-nitrophenol in a nitrifying sludge bioreactor: System performance, sludge property and microbial community shift.

The system performance, sludge property and microbial community shift were evaluated in a nitrifying sludge (NS) bioreactor for simultaneous treating p-Nitrophenol (PNP) and high ammonia wastewater. After long-term acclimation for 80 days, the removal efficiencies of PNP and NH4+-N reached to 99.9% and 99.5%, respectively. Meanwhile, the effluent PNP gradually decreased from 7.9 to 0.1 mg/L by acclimation of sludge. The particle size of NS increased from 115.2 µm to 226.3 µm accompanied by the decreased zeta potential as a self-protection strategy. The presence of PNP exposure altered the effluent soluble microbial products (SMP) fluorescent components and molecular composition. The increase in the relative abundance of Thauera, Nitrospiraceae and Nitrosomonas indicated the nitrification and denitrification capacities of NS increased, which maybe the PNP cometabolic biodegradation effect. Moreover, Ignavibacteria and Aeromonas were responsible as the dominant bacteria for degrading PNP in the nitrifying system.

Dynamic chromatic aberration pre-compensation scheme for ultrashort petawatt laser systems.

A novel chromatic aberration pre-compensation scheme for ultrashort petawatt laser systems was proposed. The pre-compensation scheme consists of a convex lens, group of concave lenses, and a spherical reflector combined with a conventional vacuum chamber. It provides a versatile method to accurately compensate the chromatic aberration of an entire laser system via controlling the amount of propagation time delay (PTD) induced by the compensator without changing the input and output beam size. A compensator, tailored based on the proposed scheme, was designed and experimentally evaluated for the Shen-Guang-II 5PW (SG-II 5PW) laser system at Shanghai Institute of Optics and Fine Mechanics (SIOM). The experimental results verified that chromatic aberration in the laser system was almost fully compensated: the size of laser beam focused by an f/2.42 off-axis parabolic mirror (OAP) was reduced tremendously from 32×18µm2to about 4×4µm2at full width at half maximum (FWHM). The proposed scheme provides the flexibility to accurately correct chromatic aberration in high-power laser systems within a wide dynamic range.

The Genome Sequence of a Novel Cyanophage S-B64 from the Yellow Sea, China.

A novel cyanophage, S-B64, which can infect marine Synechococcus WH8102, was isolated from the coastal waters of the Yellow Sea using the liquid serial dilution method. Morphological study by transmission electron microscopy revealed that the cyanophage belongs to Podovirus. It's genome, which was completely sequenced, contains a 151,867 bp DNA molecule with a G+C content of 41.78% and 186 potential open reading frames. The functions of the genes include cyanophage structure, cyanophage packaging, DNA replication and regulation. After primary characterization, it was found that the latent period is about 3 h, and it lysed after 8 h, the burst size is about 23 virions per cell. This information will provide an important benchmark for further research on the interaction between cyanophages and their hosts.

High Stress Hyperglycemia Ratio Predicts Poor Outcome after Mechanical Thrombectomy for Ischemic Stroke.

OBJECTIVE: The present study aimed to evaluate the association between stress hyperglycemia ratio (SHR) and outcome at 3 months after mechanical thrombectomy (MT) for acute occlusion in the anterior circulation. METHODS: Data from 160 consecutive patients with large vessel occlusion in the anterior circulation who underwent MT from May 2013 to March 2018 were retrospectively reviewed. SHR was calculated as the fasting glucose concentration divided by the estimated average glucose concentration (derived from the glycosylated hemoglobin level). Patients were dichotomized into 2 groups in accordance with the median SHR. Univariate and multivariate analyses were used to identify predictors of functional outcome. Good and poor outcomes were defined as modified Rankin Scale scores of 0-2 and 3-6, respectively. RESULTS: patients with unfavorable outcome had significantly higher levels of SHR than those with favorable outcome (median in SHR = 1.02 versus .84, P = .000). The median SHR was .96. Univariate analysis showed that significantly more patients with a poor outcome had SHR ≥ .96 compared with those with a good outcome (65.2% versus 31.0%, P = .000). After adjusting for potential covariates, Increased SHR (odds ratio [OR] 6.97, 95% confidence intervals [CI] 1.22-39.65, P = .029, for continuous SHR levels) and SHR ≥ .96 (OR 3.12, 95% CI 1.39-6.96, P = .006) remained independent predictors of poor outcome. CONCLUSIONS: Increased SHR is strongly correlated with poor outcome at 3 months after MT for proximal artery occlusion in the anterior circulation.

Broadband main OPCPA amplifier at 808 nm wavelength in high deuterated DKDP crystals.

The optical aperture of ultrashort extreme intensity laser facilities, which reach 10 PW, will be beyond several hundred millimeters. DKDP is by now the only nonlinear crystal that can be grown to such diameter and used in the main optical parametric chirped-pulse amplification (OPCPA) amplifier of such a laser system. Here, at the signal wavelength of 808 nm for the first time, we experimentally present a broadband OPCPA system that consists of a pre-amplifier in BBO crystals and a main OPCPA amplifier in two 95% deuterated DKDP crystals. The final amplified spectrum bandwidth exceeds 50 nm, and a compressed pulse duration of 27 fs has been measured. The conversion efficiency of the main OPCPA amplifier reached 24%, and a net signal gain of 13 was obtained. For the high energy OPCPA amplifier, the influence due to partial absorption on the idler pulses in DKDP crystal is theoretically analyzed. The results indicate the potential utilization of high deuterated DKDP for the main OPCPA amplifiers in a multi-petawatt laser system at 808 nm wavelength.

Intensive Statin Therapy for Acute Ischemic Stroke to Reduce the Number of Microemboli: A Preliminary, Randomized Controlled Study.

BACKGROUND: To assess whether intensive statin therapy reduces the occurrence of microemboli in patients with acute ischemic stroke. METHODS: Patients with acute ischemic stroke within 72 h of onset were randomized to the intensive statin (atorvastatin 60 mg/day, adjusted to 20 mg/day after 7 days) and control (atorvastatin 20 mg/day) groups. Combined aspirin and clopidogrel were used for antiplatelet therapy. Microemboli were monitored by transcranial Doppler on days 1 (pre-treatment), 3, and 7. Metalloproteinase-9 (MMP-9), high-sensitivity C-reactive protein (hs-CRP), and National Institutes of Health Stroke Scale (NIHSS) score were assessed on days 1 and 7. The modified Rankin scale (mRS) was used on day 90. The primary outcome was the proportion of patients with microemboli on day 3. RESULTS: There were 35 (58.3%) and 30 (52.6%) patients with microemboli in the intensive statin (n = 60) and control (n = 57) groups, respectively, on day 1 (p = 0.342). On day 3, there were significantly less microemboli in the intensive statin group (n = 9; 15.0%) compared with controls (n = 16; 28.1%; p = 0.002). No difference was observed in MMP-9 and hs-CRP levels on day 1, but on day 7, MMP-9 (median 79.3 vs. 95.9 µg/L; p = 0.004) and hs-CRP (median 2.01 vs. 3.60 mg/L; p = 0.020) levels were lower in the intensive statin group compared with controls. There were no differences in NIHSS scores on days 1 and 7. There was no difference in mRS on day 90. CONCLUSION: Intensive atorvastatin therapy in patients with acute ischemic stroke reduces the occurrence of microemboli and inflammation, with no overt adverse events.

Isolation and Complete Genome Sequence of a Novel Marinobacter Phage B23.

We used the double-agar layer method to isolate a novel Marinobacter marina bacteriophage, B23, from the surface water sample of the Bohai sea of China. There is some work to better understand the phage. The result of transmission electron microscopy revealed that B23 belongs to the family Siphoviridae with a head of 80 nm in diameter and a tail of 230 nm. Microbiological characterization evidenced that phage B23 is stable at the temperatures from - 25 to 60 °C, and showed vigorous vitality at pH between 4.0 and 12.0. One-step growth experiment showed that it had a longer latent period and higher lysis efficiency. Furthermore, the complete genome of B23 was sequenced and analyzed, which consists of a 35132 bp DNA with a G + C content of 59.8% and 50 putative open reading frames. The genome was divided into five parts, consisting of DNA replication and regulation, phage packaging, phage structure, host lysis and hypothetical protein.

Isolation and Complete Genome Sequence of a Novel Pseudoalteromonas Phage PH357 from the Yangtze River Estuary.

Phage PH357, a novel lytic Pseudoalteromonas lipolytica phage belonging to the Myoviridae family was isolated from the Yangtze River estuary. The microbiological characterization demonstrated that phage PH357 is stable from -20 to 60 °C and the optimal pH 7. The one-step growth curve showed a latent period of 20 min, a rise period of 20 min, and the average burst size was about 85 virions per cell. Complete genome of phage PH357 was determined. Genome of phage PH357 consisted of a linear, double-stranded 136,203 bp DNA molecule with 34.58% G + C content, and 242 putative open reading frames (ORFs) without tRNA. All the predicted ORFs were classified into eight functional groups, including DNA replication, regulation and nucleotide metabolism, transcription, translation, phage packaging, phage structure, lysis, host or phage interactions, and hypothetical protein. A phylogenetic analysis showed that phage PH357 had similarity to the previously published Pseudoalteromonas phage PH101 and Vibrio phages. Furthermore, the study of phage PH357 genome will provide useful information for further research on the interaction between phages and their hosts.

Relationship of plasma matrix metalloproteinase-9 and hematoma expansion in acute hypertensive cerebral hemorrhage.

In the present study, we aimed to investigate the relationship of plasma matrix metalloproteinase-9 (MMP-9) and hematoma expansion (HE) in acute hypertensive cerebral hemorrhage (AHCH) (HE-in-AHCH). Patients with hypertensive cerebral hemorrhage, confirmed by head computed tomography (CT) within 12 h of onset, were prospectively collected. Venous blood was sampled within 4 h of the confirmation to determine the serum MMP-9 concentration. The blood pressure and National Institute of Health Stroke Score of the patients were recorded on hospital admission. CT re-scanning was performed within 42-54 h of the first head CT examination or immediately after worsening of the patients' consciousness disorder. The relationship between MMP-9 level and HE was analyzed. A total of 186 patients were included. Of these patients, 41 had HE (22.0%). Multivariate logistic regression analysis showed that, in addition to the short interval between onset and the first CT examination, and the irregularity of hematoma shape, increasing MMP-9 level was an independent risk factor for HE-in-AHCH (OR value = 15.65, 95% CI: 5.30-46.15). Moreover, increasing plasma MMP-9 level was identified as an independent risk factor in patients with HE-in-AHCH.

The effect of early weight-bearing on bone fusion after triple arthrodesis.

Triple arthrodesis is an effective method for treating stiff horseshoe feet and severe osteoarthritis. However, it is still a challenge to improve postoperative bone fusion by changing early weight-bearing. This study improved the classical bone remodeling algorithm, established a mathematical relationship between density change rate and mechanical stimulation, and combined it with finite element theory. The proposed algorithm can not only predict the effect of early weight-bearing on triple arthrodesis but also visually demonstrate the change of bone mineral density with time. The analysis results indicated that 2.5% of the initial load was a potential factor leading to bone nonunion, and 50% of the initial load would result in bone resorption. Meanwhile, it was found that 25% of the external load was more conducive to postoperative rehabilitation. The study results have theoretical significance for enhancing the effect of postoperative bone fusion and formulating a more scientific rehabilitation program, thereby supporting patients' postoperative rehabilitation exercise.

Metagenomic insight into the acidophilic functional communities driving elemental geochemical cycles in an acid mine drainage lake.

Acidophiles play a key role in the generation, evolution and attenuation of acid mine drainage (AMD), which is characterized by strong acidity (pH<3.5) and high metal concentrations. In this study, the seasonal changes of acidophilic communities and their roles in elemental cycling in an AMD lake (pH∼3.0) in China were analyzed through metagenomics. The results showed eukaryotic algae thrived in the lake, and Coccomyxa was dominant in January (38.1%) and May (33.9%), while Chlorella in July (9.5%). The extensive growth of Chlamydomonas in December (22.7%) resulted in an ultrahigh chlorophyll a concentration (587 µg/L), providing abundant organic carbon for the ecosystem. In addition, the iron-oxidizing and nitrogen-fixing bacterium Ferrovum contributed to carbon fixation. Ammonia oxidation likely occurred in the acidic lake, as was revealed by archaea Ca. Nitrosotalea. To gain a competitive advantage in the nutrient-poor environment, some acidophiles exhibited facultative characteristics, e.g. the most abundant bacterium Acidiphilium utilized both organic and inorganic carbon, and obtained energy from organic matter, inorganic sulfur, and sunlight simultaneously. It was suggested that sunlight, rather than chemical energy of reduced iron-sulfur was the major driver of elemental cycling in the AMD lake. The results are beneficial to the development of bioremediation strategies for AMD.

Deciphering Oligodendrocyte Lineages in the Human Fetal Central Nervous System Using Single-Cell RNA Sequencing.

Oligodendrocytes form myelin sheaths and wrap axons of neurons to facilitate various crucial neurological functions. Oligodendrocyte progenitor cells (OPCs) persist in the embryonic, postnatal, and adult central nervous system (CNS). OPCs and mature oligodendrocytes are involved in a variety of biological processes such as memory, learning, and diseases. How oligodendrocytes are specified in different regions in the CNS, in particular in humans, remains obscure. We here explored oligodendrocyte development in three CNS regions, subpallium, brainstem, and spinal cord, in human fetuses from gestational week 8 (GW8) to GW12 using single-cell RNA sequencing. We detected multiple lineages of OPCs and illustrated distinct developmental trajectories of oligodendrocyte differentiation in three CNS regions. We also identified major genes, particularly transcription factors, which maintain status of OPC proliferation and promote generation of mature oligodendrocytes. Moreover, we discovered new marker genes that might be crucial for oligodendrocyte specification in humans, and detected common and distinct genes expressed in oligodendrocyte lineages in three CNS regions. Our study has demonstrated molecular heterogeneity of oligodendrocyte lineages in different CNS regions and provided references for further investigation of roles of important genes in oligodendrocyte development in humans.

[Stenting of subtotal conclusion of internal carotid artery and comparing the cerebral embolic load of proximal balloon protection device with distal filter protection device].

OBJECTIVE: To study the safety, efficacy and perioperative complications of endovascular therapy in the treatment of subtotal conclusion of internal carotid artery(ICA) in patients. To compare the cerebral embolic load of proximal balloon protection device versus distal filter protection device during the operation. METHODS: Review all the operations of stenting for subtotal conclusion of ICA in Xuanwu hospital. New cerebral infarction after stenting was assessed by diffusion-weighted magnetic resonance imaging. Count the number of new ischemic lesions of every patient. RESULTS: 35 patients with subtotal conclusion of ICA received endovascular stenting. Proximal protective device was used for 21 patients. Distal protective device was used for 14 patients. All procedures succeeded. 32 patients received the cerebral MRI 1 week before and within 48 hours after the operation. Compared with filter protection(n = 14), proximal balloon device(n = 18) resulted in a significant reduction in the incidence of new cerebral infarction (6/18 vs 10/14, P = 0.03). The number of new cerebral ischemic lesions were significant reduced by proximal balloon device (1/18 vs 4/14, P = 0.0006) . There were no serious cardiovascular events in 35 patients during the operation and the following up 3 months. 3 patients had restenosis which was demonstrated by ultrasound of ICA at 3 months after stenting. CONCLUSIONS: Endovascular stenting may be a safe and valid method for the treatment of subtotal occlusion of ICA. For the stenting of subtotal occlusion of ICA, proximal balloon protection device as compared with filter protection may reduce the embolic load to the brain more effectively. The stenting of subtotal occlusion of ICA still needs the randomized trails to confirm the safety and validity.

Sources, distribution, and environmental effects of microplastics: a systematic review.

Microplastics (MPs) are receiving increasing attention from researchers. They are environmental pollutants that do not degrade easily, are retained for prolonged periods in environmental media such as water and sediments, and are known to accumulate in aquatic organisms. The aim of this review is to show and discuss the transport and effects of microplastics in the environment. We systematically and critically review 91 articles in the field of sources, distribution, and environmental behavior of microplastics. We conclude that the spread of plastic pollution is related to a myriad of processes and that both primary and secondary MPs are prevalent in the environment. Rivers have been indicated as major pathways for the transport of MPs from terrestrial areas into the ocean, and atmospheric circulation may be an important avenue for transporting MPs between environmental compartments. Additionally, the vector effect of MPs can change the original environmental behavior of other pollutants, leading to severe compound toxicity. Further in-depth studies on the distribution and chemical and biological interactions of MPs are highly suggested to improve our understanding of how MPs behave in the environment.