Toward a fully coherent tender and hard X-ray free-electron laser via cascaded EEHG in fourth-generation synchrotron light sources.

Free-electron-laser-based beamlines utilize fully coherent laser pulses with extremely narrow bandwidth allowing direct use of X-rays without monochromators. This could be very beneficial for all users of current and future fourth-generation diffraction-limited synchrotron light sources (DL-SLSs) who need narrowband full-coherence high-brightness X-ray pulses. Based on our previous finding, i.e. that separating the two stages of echo-enabled harmonic generation (EEHG) with a few extra bending-magnet sections provides an effective way to increase the momentum compaction of chicane 1, one can simultaneously achieve adequate prebunching at extremely high harmonics as well as keep the energy modulation to the ideal minimum. This could open the door for cascaded EEHG, toward fully coherent tender and hard X-ray wavelengths. Built on our compact design of a twin-pulse seeding electron beam with an adjustable delay and timing jitter at the level of a few femtoseconds, a cascaded EEHG can be implemented, which includes two EEHG beamlines, where the radiation pulse generated by the first beamline with harmonic h1 could be used as the input seed laser pulse to the second beamline with harmonic h2. Hence, the second radiator could potentially reach very high harmonics [h = h1(20)h2(25-100)] from 500 to 2000, corresponding to tender and hard X-ray wavelengths. It is demonstrated that the cascaded EEHG scheme is compatible with almost any current or planned fourth-generation DL-SLS, with significant benefits for space-limited storage rings in particular. The main advantage is that this scheme requires almost no change of the storage-ring lattice and is fully compatible with other beamlines. Current proposals for rings with much longer straight sections would add self-amplified spontaneous emission as another viable option for storage-ring-based free-electron lasers.

Hollow Plasma Acceleration Driven by a Relativistic Reflected Hollow Laser.

In order to address the present difficulty in experimentally generating the relativistic Laguerre-Gaussian laser, primarily due to damage caused to optical modulators, a high-reflectivity phase mirror is applied in the femtosecond petawatt laser system to generate a relativistic hollow laser at the highest intensity of 6.3×10^{19} W/cm^{2} for the first time. A simple optical model is used to verify that the vortex laser may be generated in this new scheme; using such a relativistic vortex laser, the hollow plasma drill and acceleration are achieved experimentally and proven by particle-in-cell simulations. With the development of the petawatt laser, this scheme opens up possibilities for the convenient production of the relativistic hollow laser at high repetition and possible hollow plasma acceleration, which is important for a wide range of applications such as the generation of radiation sources with orbital angular momentum, fast ignition for inertial confinement fusion, and jet research in the astrophysical environment.

Thiamine ameliorates inflammation of the ruminal epithelium of Saanen goats suffering from subacute ruminal acidosis.

This study aimed to examine the role of thiamine in the local inflammation of ruminal epithelium caused by high-concentrate diets. Eighteen mid-lactating (148 ± 3 d in milk; milk yield = 0.71 ± 0.0300 kg/d) Saanen goats (body weight = 36.5 ± 1.99 kg; body condition score = 2.73 ± 0.16, where 0 = emaciated and 5 = obese) in parity 1 or 2 were selected. The goats were randomly divided into 3 groups (n = 6/group): (1) control diet (concentrate:forage 30:70), (2) high-concentrate diet (HC; concentrate:forage 70:30), and (3) high-concentrate diet with 200 mg of thiamine/kg of dry matter intake (THC; concentrate:forage 70:30). Goats remained on experimental diets for 8 wk. On the last day of 8 wk, ruminal and blood samples were collected to determine ruminal parameters, endotoxin lipopolysaccharide, and blood inflammatory cytokines. Goats were slaughtered to collect ruminal tissue to determine gene and protein expression of toll-like receptor 4 (TLR4) signaling pathways. Thiamine supplementation increased ruminal pH (6.03 vs. 5.42) compared with the HC group. Propionate (21.08 vs. 31.61 mM), butyrate (12.08 vs. 19.39 mM), lactate (0.52 vs. 0.71 mM), and free lipopolysaccharide (42.16 vs. 55.87 × 103 endotoxin units/mL) concentrations in ruminal fluid were lower in THC goats compared with HC goats. Similar to plasma interleukin 1ß (IL-1ß) concentration (209.31 vs. 257.23 pg/mL), blood CD8+ percentage (27.57 vs. 34.07%) also decreased in response to thiamine. Compared with HC goats, THC goats had lower ruminal epithelium activity of the enzymes myeloperoxidase and matrix metalloproteinase (MMP) 2 and 9. In contrast to HC, THC had downregulated mRNA expression of nuclear factor-κB (NFKB), TLR4, IL1B, MMP2, and MMP9 in ruminal epithelium. Thiamine supplementation led to lower relative protein expression of IL-1ß, NF-κB unit p65, and phosphorylated NF-κB unit p65 in ruminal epithelium. Taken together, these results suggest that thiamine supplementation mitigates HC-induced local inflammation and ruminal epithelial disruption.

[Clinicopathologic characteristics and causes of difficulty in locating the "difficult to locate" intractable epilepsy].

Objective: To summarize the clinicopathological characteristics of "difficult to locate" intractable epilepsy patients, and investigate the causes of difficulty in their location. Method: Retrospective analysis was performed on the clinical data of 58 patients who underwent resection of the epileptogenic zones after intracranial electroencephalography (iEEG) detection at the Department of Neurosurgery of the First Affiliated Hospital of Fujian Medical University from January 2010 to December 2018. Clinicopathological characteristics and lesion lobes of "difficult to locate" intractable epilepsy were summarized. The prognosis of patients was assessed according to Engel grading.Univariate and multivariate logistic regression analysis were used to investigate the relevant factors affecting the prognosis of patients with "difficult to locate" intractable epilepsy related to malformation of cortical development(MCD). Results: Among the 58 patients, there were 47 cases of MCD (12 cases with mild malformation of cortical development (mMCD), 35 cases with focal cortical dysplasia (FCD)), and 11 cases of other types. Among the 47 MCD cases, univariate analysis showed that patients with preoperative magnetic resonance imaging(MRI) positive and completed resection of the epileptogenic zones had better prognosis (P<0.05). Multivariate analysis indicated that completed resection of epileptogenic zones was an independent factor affecting the postoperative efficacy of MCD (P=0.013,Wald χ(2)=6.149, 95%CI: 0.07-0.56). And among the 47 MCD cases, 18 cases were with mono-lobar lesions and 29 cases were with multi-lobar lesions, however, there was no significant difference of the efficacy between the two groups (P=0.511). Conclusions: MCD, especially FCD, is the main pathological types of patients with "difficult to locate" intractable epilepsy. Multi-lobar pathological changes, especially multi-lobar MCD, are the main reasons of being difficult to locate, however, accurate locating of epileptogenic zones and functional areas via effective use of iEEG can achieve satisfactory efficacy in these patients after resection of the epileptogenic zones.

[Applicational value of modified pancreaticojejunostomy and risk factors of pancreatic fistula following pancreaticoduodenectomy].

Objective: To compare the efficacy of modified pancreaticojejunostomy with traditional pancreaticojejunostomy following pancreaticoduodenectomy, and to investigate the risk factors of postoperative pancreatic fistula. Methods: Clinical data of 68 patients who underwent pancreaticoduodenectomy between October 2017 and October 2018 at the Second Department of Biliary Tract Surgery, Eastern Hepatobiliary Surgery Hospital was retrospectively collected and analyzed.According to the method of pancreaticojejunostomy, the patients were divided into two groups: modified pancreaticojejunostomy group (34 patients) and traditional pancreaticojejunostomy group (34 patients). There were 18 males and 16 females, aged (60.4±9.6) years of modified pancreaticojejunostomy groups; there were 17 males and 18 females, aged (58.9±10.9) years of traditional pancreaticojejunostomy group. The major postoperative complications such as pancreatic fistula were compared between the two groups, and the risk factors of postoperative pancreatic fistula were analyzed by univariate and multivariate analyses. Results: All of the 68 operations were successfully completed. The overall incidence of postoperative complications was 51.5% (35/68). The incidence of postoperative pancreatic fistula was 13.2% (9/68), of which all were cases of grade B.There were 16 patients (23.5%) occurred with abdominal infection, and 11 patients (16.2%) occurred with delayed gastric emptying, including 1 case of grade A, 1 case of grade B and 9 cases of grade C.And 9 patients (13.2%) occurred with postoperative bleeding was, including 2 cases of mild bleeding, 5 cases of moderate bleeding, and 2 cases of severe bleeding.Biliary leakage occurred in one patient (1.5%) and chylous leakage occurred in two patients (2.9%). The modified pancreaticojejunostomy could significantly reduce the incidence of postoperative bleeding compared with control group (χ(2)=4.610, P=0.032). And there were no significant differences for other postoperative complications between the two groups (all P>0.05). According to the results of univariate analysis: age, intraoperative bleeding and diameter of pancreatic tube were related factors affecting postoperative pancreatic fistula (P=0.025, 0.019, 0.017, respectively). The results of multivariate analysis showed that intraoperative bleeding>400 ml and diameter of pancreatic tube <3 mm were independent risk factors of pancreatic fistula following pancreaticoduodenectomy (P=0.025, 0.008, respectively). Conclusion: The modified pancreaticojejunostomy is feasible with advantages of reducing postoperative bleeding following pancreaticoduodenectomy.

[Discussion on pT3 staging in TNM staging of AJCC 8(th) edition gallbladder carcinoma].

Objective: To discuss the rationality of stage pT3 in the AJCC 8(th) TNM criteria of gallbladder carcinoma. Methods: A retrospective study was performed to analyze the clinical and pathological data of 88 patients with pT3 gallbladder carcinoma admitted to Department of Second Biliary Surgery of Eastern Hepatobiliary Surgery Hospital, affiliated to Naval Medical University from May 2013 to September 2018.pT3 stage tumors were divided into two groups: (1) pT3a stage: tumors had penetrated serosa but not directly invaded liver and/or an adjacent organ or structure; (2) pT3b stage: tumor penetrating serosa and directly invaded liver and/or an adjacent organ or structure. There were 45 patients with pT3a stage, including 15 males and 30 females, aged 36 to 80 years, with a median age of 59 years; 43 patients with pT3b, including 24 males and 19 females, aged 41 to 78 years old, median aged 63 years old.Patients with pT3a and pT3b were further divided into two groups respectively: radical resection group and extended radical resection group according to surgical radicalization. Independent sample t-test was used for comparison between two groups with normal distribution measurement data. Wilcoxon rank sum test was used between groups of non-normally distributed measurement data.The comparison of the count data was performed by χ(2) test or Fisher exact probability method. Survival analysis was performed using Kaplan-Meier method, and survival rate was compared using Log-rank test. Results: (1)Serum total bilirubin(15.6(90.3)mmol/L), albumin(40.2(4.8)mmol/L), and CA19-9(132.90(455.78)U/ml) levels in pT3b patients were higher than that in pT3a patients(10.2(6.8)mmol/L, 41.8(4.9)mmol/L, 14.35(36.27)U/ml), respectively(Z=-3.816, -1.966, -3.739, all P<0.05),postoperative complication rate in pT3b patients(24.4%) was higher than that in pT3a patients(8.9%)(P<0.05),postoperative hospital stay(12(7)days) and overall hospital stay((26±17)days) of pT3b patients were longer than that of pT3a patients((10±5) days and (19±7)days) (P<0.05). (2) The 1-, 3-, 5-year survival rates of pT3b and pT3a patients were 53%,22%,22% and 69%, 46%,38%,and the median survival time was 13 months and 26 months, respectively. The difference in survival rates between the two groups was statistically significant(χ(2)=5.117, P=0.024). (3)The 1-, 3-year survival rates of extended radical resection group(n=19) and radical resection group(n=24) in the pT3b stage were 73%, 36% and 28%, 7%, respectively.The survival time was 20 months and 9 months,respectively,and the difference in survival rates between the two groups was statistically significant(χ(2)=4.976, P=0.026). Conclusions: pT3 gallbladder carcinoma could be further subdivided into pT3a stage and pT3b stage based on the TNM criteria of AJCC 8(th) gallbladder carcinoma. Extended radical resection for pT3b gallbladder carcinoma should be further considered after comprehensive assessment of the patient's basic condition and surgical tolerance.

[Neuronavigation-assisted percutaneous radiofrequency thermocoagulation of trigeminal gasserian ganglion for refractory craniofacial pain].

Objective: Percutaneous radiofrequency thermocoagulation (RFT) of the Gasserian ganglion is an effective treatment for refractory trigeminal craniofacial pain.In the present study, we assessed the feasibility of accessing the Gasserian ganglion through the foramen ovale with neuronavigation guidance in the patients of trigeminal craniofacial pain. Method: We retrospectively analyzed forty-four patients with type Ⅰ trigeminal neuralgia who had undergone percutaneous RFT treatment in our hospital from June 2014 to December 2016.The patients were divided into fluoroscopy group and navigation group according to the intraoperative guiding manners for foramen ovale cannulation.We compared groups in terms of the duration of the whole RFT procedure and times of intraoperative fluoroscopy.We also analyzed the immediate and late outcome accessing by Barrow Neurological Institute (BNI) pain scale, as well as the complication rates in groups. Result: There were 32 patients in the fluoroscopy group and 12 in the navigation group.The duration of the surgical procedure in navigation group was less than that in fluoroscopy group (46±12 min versus 67±16 min, P=0.00), and times of intraoperative fluoroscopy was reduced (6.3±2.2 versus 1.3±1.6, P=0.00). The learning curve of navigation-aid RFT was not steep in the present study overall.There was no significant difference between groups regarding pain reduction at the immediate (P=0.07) or late follow-up (P=0.400) time points.However, the rate of pain reduction to BNI-Ⅰ grade was greater in navigation group (P=0.026). No significant difference in the complication rate between both groups, and no serious complications were observed in the both groups. Conclusion: Neuronavigation may be encouraged in trigeminal Gasserian ganglion RFT with better operating efficiency and less radiation exposure.The immediate and late therapeutic effects for craniofacial pain control were positive, whereas further studies are necessary.

Effect of bamboo vinegar powder on the expression of the immune-related genes MyD88 and CD14 in weaning piglets.

The aim was to explore the feasibility of using bamboo vinegar powder as an antibiotics substitute in weaning piglets. Forty-five healthy Duroc × Landrance × Yorshire piglets (weight 6.74 ± 0.17 kg; age 31 days) were randomly divided into the control group (basic diet), ANT group (basic diet + 0.12% compound antibiotics), BV1 group (basic diet + 0.1% bamboo vinegar powder), BV5 group (basic diet + 0.5% bamboo vinegar powder) and BV10 group (basic diet + 1% bamboo vinegar powder). MyD88 and CD14 expression in immune tissues was examined using real-time PCR. MyD88 expression in the control group were significantly lower than that in other groups in all tissues (p⟨0.05), while CD14 expression showed the opposite trend. MyD88 expression was significantly higher in the BV10 group than in other groups in lung tissue (P⟨0.05), significantly higher in the ANT group than in the BV1 group in the kidneys (P⟨0.05), significantly higher in the BV10 group than in the BV1 group in the thymus (P⟨0.05), and signifi- cantly higher in the BV1 group than in the BV10 group in the lymphatic tissue (P⟨0.05). These differences between experimental groups were not observed for the CD14 gene (P>0.05). Thus, adding bamboo vinegar powder to the basic diet of weaning piglets had immune effects similar to antibiotics and the effect was dose-dependent. Moreover, the MyD88 and CD14 genes appear to play a role in these immune effects.

Effects of dietary physically effective neutral detergent fiber content on the feeding behavior, digestibility, and growth of 8- to 10-month-old Holstein replacement heifers.

The objective of this study was to evaluate the effects of dietary physically effective neutral detergent fiber (peNDF) content on the feeding behavior, digestion, ruminal fermentation parameters, and growth of 8- to 10-mo-old dairy heifers and to predict the adequacy of dietary fiber in growing dairy heifers. Twenty-four Holstein dairy heifers (245 ± 10.8 d of age, 305.6 ± 8.5 kg initial live weight) were randomly divided into 4 treatments with 6 replicates as a completely randomized design. During the 60-d period with a 10-d adaptation, heifers were offered 1 of 4 diets, which were chemically identical but included different peNDF8.0 (particle size is >8 mm and <19 mm) content (% DM): 10.8, 13.5, 18.0, or 19.8%, which was achieved by chopping forage into different lengths (fine = 1 cm, short = 3 cm, medium = 5 cm, and long = 7 cm). The concentrate and silage were mixed and fed restrictedly and exclusive of forage (Chinese ryegrass hay) were offered ad libitum. The body weight and frame size of the heifers were measured every 15 d during the experimental period. Samples of the rumen content (2 h after the morning feeding) were taken for pH, ammonia, and volatile fatty acid determination. The dry matter intake and average daily gain of the heifers were not significantly affected by peNDF8.0 content. The body frame size (including withers height, body length, and heart girth) of the heifers was not increased significantly by enhanced peNDF8.0 content. Ruminal pH and ammonia concentration were both increased with increasing dietary peNDF8.0 content. The ruminal total volatile fatty acid concentration and percentage of acetate and butyrate profiles were not significantly affected by dietary peNDF8.0 content. However, the enhanced peNDF8.0 content led to a decrease in the propionate percentage. The ratio of acetate to propionate in the 13.5% treatment was highest among the treatments. Increasing the particle size and dietary peNDF8.0 content resulted in increased eating and chewing time but had no effect on rumination time. Heifer total eating and chewing time and eating and chewing time per kilogram of dry matter intake were increased with increasing dietary peNDF8.0 content. The apparent digestibility of acid detergent fiber and crude protein was improved with an increasing content of dietary peNDF8.0. The results suggest that an optimal or advisable dietary particle size and peNDF8.0 content improves chewing activity, rumen fluid pH, and ruminal fermentation. The data based on feeding behavioral and growth responses of heifers as well as rumen fermentation and digestion by improving total eating and chewing time indicate that 18.0% dietary peNDF8.0 content is the most suitable for 8- to 10-mo-old Holstein heifers.

Nramp1 gene expression in different tissues of Meishan piglets from newborn to weaning.

Natural resistance-associated macrophage protein gene 1 (Nramp1) plays an important role in the innate immune response of swine, and is believed to influence disease resistance. In this study, a real-time quantitative polymerase chain reaction technique was used to investigate Nramp1 expression in 12 different tissues in newborn and 7-, 14-, 21-, 28-, and 35-day-old Meishan piglets. Results indicated that Nramp1 was expressed to varying degrees in all sample tissues, although expression differed among growth stages. For example, Nramp1 was highly expressed in the spleen, but minimally expressed in heart, liver, and muscle tissues among the various piglet age classes. Overall, Nramp1 expression increased with age, reaching significant levels in 21- and 28-day-old animals. Nramp1 was expressed in all 12 tissues tested; however, expression in spleen, lung, kidney, and thymus tissues was highest among newborns, which is consistent with this gene's role in innate immunity improvement. Before and after weaning, Nramp1 was highly expressed in digestive (stomach) and intestinal (duodenum, jejunum, and ileum) tissues, further indicating a genetic role in both immune regulation to compensate for weaning stress and enhanced development of intestinal immunity.

[Investigation of short-term resolution as a predictor of long-term cure of microvascular decompression in hemifacial spasm].

Objective: To investigate whether the short-term relief of spasm (within 7 days) after microvascular decompression (MVD) for hemifacial spasm (HFS) can be used as a prognostic factor of long-term outcome (>6 months). Methods: The clinical characteristics and follow-up data (completely recorded) of 159 patients who had HFS and underwent microvascular decompression surgery in the first Affiliated Hospital of Fujian Medical University from August 2008 to May 2016 were analyzed retrospectively. The collected data focus on symptom relief in a time course: immediately after MVD, 7 days after MVD and the last follow-up (>6 months) by using Cohen-Albert grading. Results: In a total of 159 patients underwent MVD were followed up for more than 6 months.Compared to persist spasm group within 7 days after MVD, the cure rate was significantly higher in the spasm symptom relief group within 7 days after MVD (P<0.05). The cure rate of MVD (y) and the number of days within 7 days of relief (x) were highly relevant, y=-0.707x(2)+ 9.724x+ 67.442 (P<0.05). By using univariate Logistic regression analysis, we found that the prognostic factors of long-term curative effect were the symptom scale immediately after MVD and the average symptom scale in the 7 days after MVD (P<0.001). The incidence of delayed cure was 41.5%(66/159). Conclusion: In the 7 days after MVD, at least 1 day of symptom remission can predict the cure of HFS.

[Factors associated with the surgical efficacy and prognosis of seizures in patients with low-grade glioma].

OBJECTIVE: To explore the relevant factors associated with the surgical efficacy and prognosis of seizures in patients with low-grade glioma (LGG). METHODS: The clinical cases of seizures in patients with LGG admitted to our department were retrospectively collected from January 2010 to December 2014. A total of 45 cases were studied to analyze the relevant factors associated with the surgical efficacy and prognosis. RESULTS: During a follow-up period of 1 to 5 years after surgery, Engel classⅠ to Ⅱ were achieved in 36 patients (80%) and Engel class Ⅲ to Ⅳ in 9 cases (20%). The preoperative epilepsy frequency and the use of intraoperative electrocardiograph (ECoG) were correlated with the surgical efficacy and prognosis (P<0.05). The other factors, such as age, gender, duration of epilepsy, and tumor characteristics, had no significant statistical difference. CONCLUSIONS: The surgical efficacy of seizures in patients with LGG is favorable. Our results suggest that preoperative epilepsy frequency and intraoperative ECoG are important factors for surgical efficacy and prognosis. Consequently, based on gross total resection for seizures in patients with LGG, epileptogenic zones should be considered and dealt with by use of ECoG.

Changes in hematological parameters in α-thalassemia individuals co-inherited with erythroid Krüppel-like factor mutations.

Phenotypic variations in α-thalassemia mainly depend on the defective α-globin gene number. Genetic modifiers of the phenotype of Hemoglobin H (HbH) disease were poorly reported, apart from ß-thalassemia allele that was identified ameliorating the severity of α-thalassemia. Because erythroid Krüppel-like factor (KLF1) mutations can modulate the red blood phenotype, we evaluated its effect on the α-thalassemia phenotype. Overall, we identified 72 subjects with five different KLF1 heterozygous mutations in 1468 individuals, including 65 out of 432 α-thalassemia carriers with fetal hemoglobin (HbF) levels ≥1%, 0 out of 310 carriers with HbF levels <1% and 7 out of 726 HbH disease patients. We firstly established the link between KLF1 mutations and relatively elevated hemoglobin A2 (HbA2 ) and HbF levels, along with lower mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) values in a group of α-thalassemia carriers. However, we concluded that KLF1 mutations were not significantly linked to HbH disease severity. On the basis of HBA or HBB genotype and gender, clinical severity of patients with HbH disease was correctly predicted in 73.3% cases. It may improve the screening and diagnostic assessment of α-thalassemia.

PI3K-AKT pathway polymerase chain reaction (PCR) array analysis of epilepsy induced by type II focal cortical dysplasia.

The aims of this study were to observe the differential expression of PI3K-AKT pathway-related genes in seizure-inducing brain lesions in type II focal cortical dysplasia, and to explore the relationship between gene expression and histological changes in dysplastic foci and their epileptogenic mechanism. Typical lesions in brain tissue from three patients with epilepsy induced by type II focal cortical dysplasia were selected for analysis, along with normal brain tissue from two control group individuals. Following quantitative expression analysis using the RT2 Profiler(TM) PI3K-AKT PCR Array, differential expression of the pathway related genes was detected in the focal brain tissue lesions, and gene function queries were performed. Compared with the control group, thirteen related genes appeared to exhibit marked differences in expression in epileptic lesions from patients with type II focal cortical dysplasia; those genes were found to be involved in regulation of cell size, morphology, adhesion, migration, and apoptosis, and in immunity, inflammation, and many other domains. The differential expression of multiple genes in the PI3K-AKT signaling pathway in type II focal cortical dysplasia may be an important molecular mechanism underlying histological changes and recurrent seizures.

Twin-pulse seeding enables pump-probe capabilities in the EUV to soft X-ray spectrum at synchrotron light sources.

Having previously reported that separating the two stages of echo-enabled harmonic generation (EEHG) with one or more bending magnet (BM) sections allows the BMs to serve as the desired source of momentum compaction, here we demonstrate that this arrangement can greatly reduce the total energy modulation required by any 4th generation synchrotron light source, leading to higher repetition rates as well as stronger coherent radiation output power, with significant benefits. Since the EEHG beamline performance is mainly determined by the momentum compaction, beam emittances and beta functions of a storage ring lattice, allowing for different separations between the two stages is a straightforward way to increase the momentum compaction of chicane 1. This also enables pump-probe capabilities in a novel context, where twin-pulse seeding on the same electron bunch would allow two distinct radiation pulses with an adjustable delay in the range of 0.1 to 10 ps. In the twin-pulse seeding scheme, the same electron bunch could undergo modulation from two distinct laser pulses. Later stages would produce independent harmonics in subsequent straight sections. There are two variations of this twin-pulse seeding scheme, supporting different scientific applications. With a common modulation in stage 1, the first option allows simultaneously two independent radiation sources, with a full coverage of the EUV (2.5 to 50 nm) to soft X-ray (1.25 to 2.5 nm) spectrum; for the second option, the same stage 2 undulator could generate two coherent pulses both fitting within the FEL bandwidth, or at distinct harmonics. We present particle tracking simulation studies based on the APS-U lattice, including quantum excitation and radiation damping. These simulations indicate that there is no degradation of the modulated longitudinal phase space even when the two stages are separated by as many as 10 BM sections.

Molecular characterization and functional analysis of sheep thyroid transcription factor-1.

Thyroid transcription factor-1 (TTF-1), a member of the Nkx2 family of homeodomain-containing proteins, is involved in binding to and in activating the promoters of several important genes in the thyroid, lungs, and brain, and in regulating expression of these tissue-specific genes. We investigated potential roles of sheep (Ovis aries) TTF-1 in regulating cell fate and organ morphogenesis and in controlling puberty and reproductive capability of females. We amplified and cloned the sheep TTF-1 full-length DNA for the first time, analyzed its functional domains and regions, predicted molecular structure of its homeodomain and DNA-binding sites, and examined its expression in pituitary, brain, thyroid gland, ovary, and hypothalamus. We found that sheep TTF-1 has a high degree of homologous identity with that of other mammals, and it has several important domains including domain N, DNA-binding domain, domain C, TN-domain, domain I, and NK2-SD. The DNA-binding domain of sheep TTF-1 has 10 potential DNA-binding sites and is a novel mammalian homeodomain that shows considerable sequence homology with the corresponding rat homeodomain. Several functional regions in sheep TTF-1 share high sequence identity with rat TTF-1, indicating that these regions may have the same activity as in the rat. Expression of TTF-1 in several specific tissues implies that sheep TTF-1 in involved in sheep sexual development and reproductive capability. These results suggest a role of sheep TTF-1 in enhancing sheep reproduction performance and we propose it as a candidate gene for selection.

Optimization of echo-enabled harmonic generation toward coherent EUV and soft X-ray free-electron laser at NSLS-II.

Prebunching via echo-enabled harmonic generation (EEHG) is an efficient way to reduce the radiator length and improve the longitudinal coherence as well as output stability in storage-ring-based free-electron lasers. We propose a conceptual design, which uses two straight sections to seed coherent extreme-ultraviolet (EUV) and soft X-ray emission with nearly MHz repetition rate. To take the large energy spread (10-3) of a storage ring into account and utilize the existing bending magnets between the two straight sections as the first chicane, we implement a special modeling tool, named EEHG optimizer. This tool has been successfully applied to maximize the prebunching with a reasonably low energy modulation, thereby generating intense coherent X-ray pulses within a short undulator length (a few meters) limited by the available space of a storage ring. Numerical simulations confirm that the optimized EEHG parameters can be directly applied to generate a 10 MW scale peak power with fully coherent ultrafast EUV to soft X-ray pulses based on the NSLS-II parameters. This method can be easily extended to other types of diffraction-limited storage rings.

Toward fully coherent soft x-ray free-electron laser via echo-enabled harmonic generation in fourth generation synchrotron light sources.

Having previously reported on bunching via echo-enabled harmonic generation (EEHG) as an effective way to improve the longitudinal coherence in the NSLS-II storage ring [X. Yang et al., Sci. Rep. 12, 9437 (2022)], we demonstrate that this EEHG scheme can be easily adopted to any fourth generation diffraction-limited synchrotron light source with significant benefits. The advantage of the scheme is that it requires no change of the lattice and is fully compatible with other beamlines. Since the EEHG performance is mainly determined by the momentum compaction, beam emittances, and beta functions of a SR lattice, we have identified these crucial parameters and successfully built a generalized model, which can predict the performance of nearly any SLS. Regarding the fourth generation SLSs, momentum compactions are often significantly smaller; thus, to cover the x rays with a photon energy of up to 1 keV, we utilize a specific design, including a 250 nm seed-laser wavelength. Our model predicts that for most of the current and future fourth generation SLSs, the EEHG scheme can produce significant prebunching up to harmonic 200 and, thus, generate a few MW scale peak power at 1.25 nm wavelength.

[Preliminary analysis of the promotion effect of laparoscopic standardized surgical treatment for gastric cancer in regional medical centers in Shanghai].

Objective: To explore the promotion effect of laparoscopic standardized surgery for gastric cancer observational in some regional medical centers in Shanghai. Methods: A retrospective cohort study was carried out. Eleven regional medical centers in Shanghai received the promotion program of laparoscopic standardized surgery for gastric cancer, which was led by Ruijin Hospital, Shanghai Jiaotong University School of Medicine (Shanghai Minimally Invasive Surgery Center) from January to December 2020. Clinicopathological data of gastric cancer patients treated at these 11 regional medical centers before and after the promotion program were collected. Inclusion criteria were as follows: patients undergoing laparoscopic distal gastrectomy or total gastrectomy; gastric cancer confirmed by pathology; without distant metastasis or peritoneal metastasis. Patients who did not undergo laparoscopic D2 radical resection, or received neoadjuvant chemotherapy before surgery, or without complete clinical data were excluded. Patients undergoing laparoscopic surgery from January to December 2019 were included in the pre-promotion group (46 cases). Patients undergoing laparoscopic surgery from January to December 2021 were included in the post-promotion group (102 cases). In addition, patients undergoing laparoscopic surgery at Ruijin Hospital from January 2021 to December were included in the control group (138 cases). The baseline data, perioperative measurements postoperative complications, and pathological results of the three groups were analyzed and compared. Results: There were no significant differences in baseline characteristics among the three groups (all P>0.05). Compared with the pre-promotion group, the operation time in post-promotion group was significantly shorter [(207.3±36.0) minutes vs. (254.2±47.1) minutes, t=7.038,P<0.001], and the number of harvested lymph node was significantly more (24.4±12.2 vs. 18.9±5.5, t=2.900, P=0.004). However, there were no significant differences in the extent of resection, time to fluid intake, and postoperative hospital stay between the two groups (all P>0.05). Compared with the control group, the operation time [(207.3±36.0) minutes vs (172.6±26.0) minutes, t=8.281, P<0.001], time to fluid intake [(6.3±3.2) days than (5.5±3.0) days, t=2.029, P=0.044], and the postoperative hospital stay [(14.3±5.6) days vs. (10.1±4.8) days, t=6.036, P<0.001] in the post- promotion group were still longer. Total gastrectomy was less common in the post-promotion group compared with the control group [18 cases (17.6%) vs. 41 cases (29.7%), χ2=7.380, P=0.007]. However, there was no significant difference in the number of harvested lymph node between the two groups (P>0.05). The morbidity of postoperative complication in the post-promotion group (9.8%, 10/102) was significantly lower than that in the pre-promotion group (23.9%, 11/46) (χ2=5.183, P=0.023), while above morbidity was not significantly different between the post-promotion group and the control group [9.8% vs. 6.5% (9/138), χ2=0.867, P=0.352]. Conclusion: After the promotion of laparoscopic standardized surgery for gastric cancer in regional medical centers, the standardization degree of surgery has been improved, and the morbidity of postoperative complication decreases. Laparoscopic standardized surgery for gastric cancer can be promoted to more regional medical centers.