[A survey on the current status and related factors of influenza vaccination among health care workers in tertiary hospitals of Xining city during the influenza epidemic season from 2017 to 2018]

Objective: To evaluate the current status and related factors of influenza vaccination among health care workers (HCWs) in tertiary hospitals of Xining city after the implementation of the free influenza vaccination policy. Methods: In August 2018, the cluster sampling method was used to select four medical institutions in Xining that had previously conducted investigations and interventions. All HCWs(excluding logistic staff) in each medical institution were included in the study. A total of 3 260 valid respondents were included. Questionnaires were used to collect the demographic characteristics, influenza and influenza vaccination awareness, implementation of free policy in the influenza epidemic season from 2017 to 2018, influenza vaccination status, awareness of influenza vaccination schedule and free policy. The multivariate logistic regression model was used to analyze related factors of influenza vaccination. Results: The age of respondents was (31.41±5.00) years. The influenza vaccination rate was 6.80% (226/3 260) in 2017-2018 influenza epidemic season. After controlling for related factors, the awareness of the influenza vaccination schedule (OR=17.05, 95%CI: 5.86-49.59), vaccination frequency (OR=8.22, 95%CI: 2.98-22.61) and the free policy (OR=3.15, 95%CI: 1.49-6.67) had higher vaccination rate. Conclusion: The influenza vaccination rate of HCWs in tertiary hospitals of Xining city was low. Increasing the awareness of the vaccination schedule, frequency and free policy may promote the influenza vaccination rate of HCWs.

[Role of a liver pathology standardized scoring system in the diagnosis of congenital biliary atresia and its relationship with prognosis]

Objective: To evaluate the diagnostic value of a histologic scoring system in congenital biliary atresia and its prognostic relevance. Methods: From January 2017 to June 2018 at Children's Hospital of Fudan University, 172 wedge liver biopsy specimens were obtained from infants with neonatal cholestasis [119 patients with congenital biliary atresia (CBA) and 53 patients with non-obstructive cholestasis as control]. A pathologist, single-blinded to the final diagnosis, made the histological diagnosis individually based on an 8-feature (portal ductal proliferation, bile duct reaction, bile plugs in portal ductules, liver fibrosis, edema in portal region, cholestasis, inflammatory cells infiltration in portal region, and ductal plate malformation), 21-point scoring system. Results: The main pathologic changes of biliary atresia were hepatocyte cholestasis, hyperplasia of bile ducts, fibrosis and infiltration of inflammatory cells in the portal area. There were significant difference in the degree of portal edema, bile duct hyperplasia and fibrosis between two groups (P<0.01). In addition, there were characteristic bile duct thrombosis in 97.5%(116/119) of the cases and abnormal development of bile duct plate in 9.2%(11/119) of the cases. Compared with non-CBA infant cholestasis group, the difference was statistically significant (P<0.05). The scoring system has high sensitivity, specificity (both 94.1%) and accuracy (94.3%) in the diagnosis of CBA. A score equal to or more than 11 points supported a diagnosis of CBA; whereas a score less than 11 points might suggest cholestasis. The degree of hepatic fibrosis and ductal plate malformation were related to prognosis. Conclusions: The liver pathology scoring system (8-feature, 21-point) is more accurate in diagnosing CBA than previous methods, which may guide the clinicopathological diagnosis. This histological scoring system also helps to assess the prognosis of CBA.

[Clinicopathological features and prognosis of pediatric alveolar rhabdomyosarcoma]

Objective: To investigate the clinicopathological features, diagnosis, differential diagnosis, treatment and prognosis of pediatric alveolar rhabdomyosarcoma (ARMS). Methods: The clinical and pathological data of 25 pediatric ARMS from 2008 to 2018 in Children's Hospital of Fudan University were collected. This histomorphology was assessed, and FOXO1 gene rearrangement was detected with FISH. The treatment details and outcome were analyzed. Results: There were 13 males and 12 females, with ages range from 19 days to 14 years (median 6 years, mean 6.2 years). The ARMS were located in the limbs (13 cases), head and neck (4 cases), trunk (3 cases), abdominal cavity (3 cases), scrotum (1 case) and perianal region (1 case). The ARMS were classified histologically as classic group (18 cases), solid group (5 cases) and embryonic-alveolar mixed group (2 cases). The typical pathological characteristics were small dark round cells arranged in solid, glandular and papillary patterns. The tumor cells expressed ALK (D5F3) (21/25, 84.0%), muscle origin DES (23/25, 92.0%), myogenin (22/25, 88.0%), MYOD1 (19/25, 76.0%), and in some cases they also expressed neurogenic marker Syn (6/25, 24.0%). FOXO1 gene rearrangement was detected by FISH in 24/25 cases (96.0%). Conclusion: Pediatric ARMS is rare and has unique clinicopathological characteristics, and needs to be differentiated from other common small round cell malignancies in children. ALK, DES, myogenin, MYOD1 immunohistochemistry and FOXO1 gene rearrangement are valuable aid in the diagnosis of ARMS.

[Clinicopathological analysis of infantile/congenital fibrosarcomas with rare histological features]

Objective: To analyze the clinicopathological features, immunohistochemical (IHC) phentotype,diagnosis and differential diagnosis of infantile/congenital fibrosarcoma (IFS/CFS) with unusual histological features. Methods: Five IFS/CFS at Children's Hospital of Fudan University from March 2014 to July 2018 were analyzed for their diagnosis and differential diagnosis. Results: Two cases were males, three cases were females. The clinical manifestation of IFS/CFS was a rapidly-growing and painless mass. There were no specific radiologic features. Histologically, the tumor cells are arranged in intersecting or sheet-like patterns. There were focal hemangioma-like areas in four cases. There were also focal areas of primitive asteroid, short-spindled, and oval tumor cells in three cases. IHC study showed the tumor cells diffusely expressed TLE1(2/5), Vimentin(5/5), and WT1(3/5), in a cytoplastic pattern; they focally expressed CD34(3/5), CD31(3/5), and α-SMA(2/5). Fluorescence in situ hybridization (FISH) detected break-apart positivity of ETV6 gene. Conclusions: Hemangioma-like pattern, myxoid area, and TLE1 expression is very rare in IFS/CFS. Detection of ETV6 gene break-apart by FISH is very helpful in the diagnosis and differential diagnosis of IFS/CFS.

[Risk factors and sonographic findings associated with the type of placenta accreta spectrum disorders]

Objective: To evaluate the risk factors and sonographic findings of pregnancies complicated by placenta increta or placenta percreta. Methods: Totally, 2 219 cases were retrospectively analyzed from 20 tertiary hospitals in China from January 2011 to December 2015. The data were collected based on the original case records. All cases were divided into two groups, the placenta increta (PI) group (79.1%, 1 755/2 219) and the placenta percreta (PP) group (20.9%, 464/2 219) , according to the degree of placental implantation. The risk factors and sonographic findings of placenta increta or percreta were analyzed by uni-factor and logistic regression statistic methods. Results: The risk factors associated with the degree of placental implantation were age, gravida, previous abortion or miscarriage, previous cesarean sections, and placenta previa (all P<0.05), especially, previous cesarean sections (χ(2)=157.961) and placenta previa (χ(2)=91.759). Sonographic findings could be used to predict the degree of placental invasion especially the boundaries between placenta and uterine serosa, the boundary between placenta and myometrium, the disruption of the placental-uterine wall interface and loss of the normal retroplacental hypoechoic zone(all P<0.01). Conclusions: Previous cesarean sections and placenta previa are the main independent risk factors associated with the degree of placenta implantation. Ultrasound could be used to make a prenatal suggestive diagnosis of placenta accreta spectrum disorders.

[Influenza vaccination and its influencing factors among clinical staff of the hospitals in 2016-2017 season, Xining, Qinghai province, China]

Objective: To investigate the influenza vaccination and its influencing factors among the clinical staff in Xining, Qinghai province, in the 2016-2017 influenza season, and to explore the promoting strategies to encourage the target population for influenza vaccination. Methods: Four sample hospitals were randomly selected from the total 11 tertiary hospitals in Xining city. Clinical staff that worked in the four hospitals and agreed to participate were recruited for investigation via a self-administered questionnaire. Results: During the 2016-2017 influenza season, the coverage rate of influenza vaccines among the clinical staff was 5.14% (95%CI: 4.80%-5.49%). Multivariate logistic regression showed that knowing the priority of vaccination, the frequency of vaccination, effect of vaccination, and possessing higher professional qualifications were major influencing factors for influenza vaccination. The intention on recommendation of seasonal influenza vaccine was higher in vaccinated group than that in the unvaccinated group (χ(2)=99.57, P<0.001). Conclusion: The lower coverage rate was primarily associated with the lack of knowledge about influenza vaccine among the clinical staff of the hospital. Tailored information should be provided to the clinical staff through effective methods to improve vaccination and the recommendation of influenza vaccine.

[Effects of inhibiting the phosphorylation of JNK by absorbed INF-γon the remodeling of nasal mucosa in allergic rhinitis rats]

Objective:To study the role of phosphorylated JNK(c-Jun N-terminal kinase) on nasal mucosa remodeling in allergic rhinitis(AR) rats and the influence of IFN-γon IL-1β,JNK and nasal mucosa remodeling.Method:According to random number table,48 Wistar rats were divided into control group(A group),AR group(B group),IFN-γgroup(C group) and triamcinolone acetonide group(D group).The rats in group B,C and D were sensitized and provocated for inducing AR by intraperitoneal injection of ovalbumin(OVA) and Al(OH)₃.Thirty minutes before intranasally challenged,rats in three groups were administrated by instillation of PBS,IFN-γand triamcinolone acetonide into nasal cavities,while the group A rats were administrated by saline solution.Ten rats in each group were selected to enter the final experiment.The density of IL-1βin serum and nasal lavage fluid were tested by ELISA.The mean absorbance (mA) of phosphorylated JNK and c-Jun were tested by immunohistochemistry.Western Blot detected the P-JNK level in nasal tissue homogenate.Result:The density of IL-1βin serum and nasal lavage fluid in group C and group D were significantly lower than that of group B (P<0.01).Immunohistochemistry study showed that the protein expression level of phosphorylated JNK and c-Jun of nasal mucosa were significantly increased in group B,but significantly reduced in group C and group D .The mA of phosphorylated JNK and c-Jun in group B were significantly higher than those in the group C and group D(P<0.01).The Western blot showed that the P-JNK of nasal tissue homogenate in group B was higher than that of group C and group D (P<0.01).Conclusion: The phosphorylation of JNK played an important role in nasal mucosa remodeling.IFN-γcould inhibit the phosphorylation of JNK and reduce the nasal mucosa remodeling.The mechanisms may be achieved through down-regulation of IL-1β.

[Contrast study of double-balloon catheter with and without oxytocin for cervical ripening]

Objective: To evaluate the efficacy and related issues for cervical ripening by double-balloon catheter with and without oxytocin. Methods: The prospective non-randomly control research was conducted from March 2015 to June 2017 in Yuquan Hospital of Tsinghua University. The primipara with induced labor indications and balloon placement conditions were divided into two groups. Seventy-eight cases were in the balloon with oxytocin group, in which oxytocin was used if there were no contraction 1 hour after balloon placement. Meanwhile, 220 cases were in the single balloon group. Before and after balloon placement, the changes of cervical Bishop Scores and delivery outcome were compared between the groups. Results: The effective rate of cervical ripening in the balloon with oxytocin group was higher than that in the balloon group[92.3% (72/78) vs 82.7% (182/220), P<0.05], the proportion of parturiency within 12 hours was as well[15.4% (12/78) vs 7.3% (16/220), P<0.05]. The effective rate of cervical Bishop score 4-5 points was further improved in the balloon with oxytocin group[95.7%(66/69) vs 85.1% (165/194), P<0.05]. Taken out balloon, the cervical Bishop scores (8.1±1.1) points in the balloon with oxytocin group were higher than (6.5±1.2) points in the balloon group (P<0.05). For the maternal without parturiency in the balloon with oxytocin group, the cervical Bishop score reduced from (7.7±0.9) points to (6.6±0.6) points after removal balloon for 12 hours (P<0.05). The cesarean section proportion for intrauterine infection in the balloon with oxytocin group was higher than that of the balloon group ( P<0.05), but the placental pathological diagnosis proportion was no significant difference ( P>0.05). In the two groups, the cesarean section rate, the first labor stage, the episiotomy rate, the postpartum hemorrhage rate, neonatal weight, the neonatal asphyxia and referral rate showed no significant differences (P>0.05, respectively). Conclusions: The double-balloon catheter with oxytocin can further improve the efficiency of patients with cervical Bishop score 4-5 points for cervical ripening , and increase the chance of labor in 12 hours.

Simultaneous removal of aqueous Zn2+, Cu2+, Cd2+, and Pb2+ by zeolites synthesized from low-calcium and high-calcium fly ash

In this study, zeolites were synthesized from low-calcium (LCZ) and high-calcium (HCZ) fly ash, respectively. Subsequently, the zeolites were tested for their removal effectiveness for four aqueous cations, namely, Zn²⁺, Cu²⁺, Cd²⁺, and Pb²⁺, as a function of contact time, pH value, adsorbent dosage, and initial concentration of heavy metals. Both zeolites were characterized by X-ray diffraction, X-ray fluorescence spectrometry, scanning electron microscopy, specific surface area, and cation exchange capacity. The results show that HCZ mainly consists of an unnamed zeolite (Na₆[AlSiO₄]₆·4H₂O), whereas LCZ mainly consists of faujasite-type zeolite. The optimum sorption conditions were pH = 6.0; adsorbent dosage = 1.0 g·L^-1; temperature = 25 °C; contact time = 100 min; and initial heavy metal concentration = 100 mg·L^-1. The sorption kinetics of the four aqueous cations on both LCZ and HCZ followed the pseudo-second-order kinetic model, and the sorption isotherm data fitted well with the Langmuir isotherm model. For LCZ, the maximum adsorption capacities of Zn²⁺, Cu²⁺, Cd²⁺, and Pb²⁺ were 155.76, 197.86, 123.76, and 186.22 mg·g^-1, respectively. For HCZ, the values were 154.08, 183.15, 118.91, and 191.94 mg·g^-1, respectively. The zeolites were regenerated by NaCl solution (1 mol·L^-1) and showed high removal efficiency. In conclusion, zeolites produced by fly ash are promising materials for removing Zn²⁺, Cu²⁺, Cd²⁺, and Pb²⁺ from wastewater.

[Treatment outcome evaluation of different mandibular advancements using oral appliance to treat obstructive sleep apnea and hyponea syndrome: a systematic review]

OBJECTIVE

To evaluate the polysomnology results along with mandibular titrated advancement using oral appliance to treat obstructive sleep apnea and hyponea syndrome (OSAHS).

METHODS

Several electronic databases (PubMed, Embase, Cochrane Library, CNKI, VIP, and Wanfang) were systematically searched up to September 2015. There was no restriction of language or source of information. All randomized clinical trials (RCT) and before-after trials (BAT) comparing at least two different mandibular advancements were included. Two independent reviewers selected the studies, extracted data and evaluated risk of bias by quality assessment. Data were pooled using a fixed-effects model, and the summary effect measure was calculated by risk ratio (RR) and 95%CI. Meta-analysis was performed using RevMan 5.3 software.

RESULTS

Two RCTs and five BATs were included in the review. Among the five BATs, two of them were randomized, while the other three were not. Outcomes including apnea hypopnea index (AHI), oxygen desaturation index (ODI), success rate (reduction of AHI or ODI >50%), normalization rate (AHI or ODI<10/h) were assessed in this review. Based on the trial design and quality assessment, four studies were included for meta-analysis. No significant difference in the success rate was found between the group with 50% of the maximal mandibular advancement (MMA) and the group with 75% of MMA [I²=0%, RR=0.93, with 95%CI (0.80, 1.09)]. No significant difference in the normalization rate was found between the 50% of MMA and 75% of MMA groups [I²=45%, RR=0.85, with 95%CI (0.68, 1.06)]. Subgroup analysis displayed that the severity of OSAHS before treatment was a potential factor affecting the normalization rate.

CONCLUSION

Based on current available evidence, the success rate and normalization rate for treating OSAHS in the patients with 75% MMA were not found to be significantly higher than those with 50% MMA. Due to small simple size in this meta-analysis, the results of the present study should be interpreted with caution. Further prospective studies are needed to strengthen the evidence.

[Risk factors of central neck lymph node metastasis in cN0 papillary thyroid carcinoma]

Objective:To investigate the risk factors of central neck lymph node metastasis (CNLNM) in cN0 papillary thyroid carcinoma. Method:Retrospective analysis of 114 patients with papillary thyroid carcinoma in stage of cN0 who underwent primary treatment. Collected the clinical and pathological data, used the univariate and multivariate analysis to investigate the risk factors of central neck lymph node metastasis and high volume central neck lymph node metastasis.Result:In the univariate analysis, age (48.2% in<45 years vs 27.6% in≥45 years), multifocal (51% with vs 27.7% without), nodular goiter (58.8% with vs 28.7% without), showed significant difference in prevalence of CNLNM. Age (14.3% in<45 years vs 1.7% in≥45 years), tumor size (19.2% >1 cm vs 4.5%≤1 cm) showed significant difference in prevalence of high volume CNLNM. Inmultivariate analysis, age (RR= 0.304), multifocal (RR= 3.637) and nodular goiter (RR= 4.132) showed the independent risk factor of CNLNM.Conclusion:For cN0 patients with thyroid papillary carcinoma, if the age is younger than 45 years old, the tumor is multifocal, or associatedwith nodular goiter, the surgery should be more aggressive in the prophylactic central neck dissection.

[A cross-sectional study of cataract in residents with type 2 diabetes living in Xinjing Town, Shanghai]

Objective: To investigate the prevalence, subtypes and risk factors of cataract in type 2 diabetic individuals. Methods: Geographically defined cluster sampling method was used in this population-based, cross-sectional study. There were 7 756 type 2 diabetes individuals in Xinjing Town with a residential population of 88 864. The type 2 diabetic individuals were randomly selected from 20 basic sample units in Xinjing Town of Changning District from April to June 2016. All participants received visual acuity measurement and eye examination. The standard of lens opacity assessment was according to the Lens Opacities Classification SystemⅡ(LOCSⅡ). The prevalence of cataract in diabetic individuals was calculated with LOCS≥2. Multivariate Logistic regression analysis was used to explore the relevant factors of cataract in type 2 diabetic individuals. Results: A total of 1 719 type 2 diabetic individuals were included in the analysis. There were 682 men (39.67%) and 1 037 women (60.33%) in this population. There were 434 cataract individuals and the prevalence of cataract was 25.25%. There were 269 cases of nuclear type (15.7%), 38 cases of cortical type (2.2%), 2 cases of posterior subcapsular type (0.12%) and 42 cases of mixed type (2.4%) in the 1 719 individuals. Multivariate Logistic regression analysis showed that age (P<0.001), duration of diabetes (P<0.001), education (P=0.005), fasting blood glucose (P(6.1-7.7mmol/L)=0.025, P(7.8-24.3mmol/L)=0.022, compared with 3.6-6.0 mmol/L of fasting blood glucose), and ocular axial length (P<0.001) were associated with cataract. Conclusion: Cataract is a common ophthalmic disease in adults with type 2 diabetes in Xinjing Town. Regular screening of diabetes in the high risk population and intensive control of both glucose and blood pressure in diabetic patients are recommended to prevent and delay the development of cataract. (Chin J Ophthalmol, 2017, 53: 489-494).

[Genetic analysis of a pedigree with primary hypertrophic osteoarthropathy]

Objective: To analyze the clinical and genetic features of primary hypertrophic osteoarthropathy (PHO). Methods: The clinical data of one Chinese pedigree of PHO, namely pachydermoperiostosis (PDP) were collected.Blood samples were drawn from the propositus and other family members.DNA was extracted and genetic analysis was performed by Sanger method after PCR.The sequencing data of HPGD gene exons were analyzed by alignment with sequences from National Center for Biotechnology Information (NCBI). Results: (1)The propositus represented symptoms in childhood including clubbing fingers, sweating, seborrhea, joint swelling and so on.Periosteal thickening and bone hyperplasia were found by X-ray. (2)The homozygous mutation named c. 310_311delCT in propositus, which located in the third exon of HPGD, was identified.His parents carried the same heterozygous mutation, while his sister did not inherit any mutation of this gene. (3)The prediction of spatial structure of proteins revealed that the mutant proteins had about 60% discrepancy compared with wild-type protein, losing a lot of motifs responsible for combining with coenzyms and prostaglandin E(2), as well as active sites of enzymes. Conclusions: The clinical manifestations and imaging findings are helpful to diagnose PDP. Moreover gene mutation analysis ensures the diagnosis.The structure and function of HPGD gene mutation induce 15-hydroxy prostaglandin dehydrogenase mutation, contributing to the occurrence of PDP.

[Primary neuroendocrine carcinoma of the tonsil: two case reports and review of the literature]

Neuroendocrine carcinoma(NEC) of the tonsil is extremely rare. Only a few cases of this tumor have been reported so far. In this article, we described two patients presented with abnormal sensation of throat or throat pain. The pathological examination were NEC. With review of the literatures, the clinical characteristics were summarized and therapeutic strategies were discussed.

Epidemiology, species distribution, antifungal susceptibility, and ERG11 mutations of Candida species isolated from pregnant Chinese Han women

The widespread use of antifungal agents has led to increasing azole resistance in Candida species. A major azole-resistance mechanism involves point mutations in the ERG11 gene, which encodes cytochrome P450 lanosterol 14a-demethylase. In this study, vaginal swabs were obtained from 657 pregnant Chinese Han women and cultured appropriately. The open reading frame of the obtained fungal species were amplified by PCR and sequenced; additionally, the ERG11 gene of the isolated Candida species was amplified and sequenced, and the antifungal susceptibility of the isolated species was determined. The vaginal swabs of 124 women produced fungal cultures; five species of Candida were isolated from the patients, among which Candida albicans was predominant. Twelve C. albicans isolates (13.8%) were resistant to fluconazole and 2 (2.2%) were resistant to itraconazole. Seventeen mutations, including 9 silent and 8 missense mutations, were identified in the ERG11 gene of 31 C. albicans isolates. Our findings suggest that infection caused by C. albicans and non-C. albicansis common in Chinese Han women of reproductive age. Moreover, the relationship between Candida infection and certain epidemiological factors emphasizes the need to educate women about the precise diagnosis and punctual treatment of vaginitis.

Respiratory chain complex III deficiency in patients with tRNA-leu mutation

The aim of this study was to investigate the clinical and genetic profiles of mitochondrial disease resulting from deficiencies in the respiratory chain complex III. Three patients, aged between 8 months and 12 years, were recruited for this study. The activities of mitochondrial respiratory chain complexes in the peripheral leucocytes were spectrophotometrically measured. The entire mitochondrial DNA (mtDNA) sequence was analyzed. Samples obtained from the three patients and their families were subjected to restriction fragment length polymorphism and gene sequencing analyses. mtDNA copy numbers of all patients and their mothers were analyzed. The patients displayed nervous system impairment, including motor and mental developmental delay, hypotonia, and motor regression. Two patients also suffered from Leigh syndrome. Assay of the mitochondrial respiratory chain enzymes revealed an isolated complex III deficiency in the three patients. The m.3243 A>G mutation was detected in all patients and their mothers. The mutation loads were 48.3, 57.2, and 45.5% in the patients, and 20.5, 16.4, and 23.6% in their respective mothers. The leukocyte mtDNA copy numbers of the patients and their mothers were within the control range. The clinical manifestation and genetics were observed to be very heterogeneous. Patient carrying an m.3243 A>G mutation may biochemically display a deficiency in the mitochondrial respiratory chain complex III.

Generation of bright attosecond x-ray pulse trains via Thomson scattering from laser-plasma accelerators: errata

We report and correct a couple of calculation errors in the x-ray flux and maximum peak brightness in our paper [Opt. Express 22, 32098 (2014)].

Fibroblastic rheumatism: the first case with infiltration of multinuclear giant cells and raised blood lead level

Fibroblastic rheumatism (FR) is a rare condition characterized by symmetrical polyarthritis and multiple cutaneous nodules. Approximately 30 cases have been reported worldwide to date. Laboratory tests are not particular useful to confirm the disease. Diagnosis is mainly dependent on the characteristic histopathological features: thickened collagen fibres with spindle-shaped cell proliferation in the skin lesion. We report a case of a 48-year-old Chinese man with typical clinical features of FR. In addition to the characteristic histopathological findings, multinuclear giant cell infiltration in skin lesions was detected, in this case. The evaluation of microelements revealed a raised blood lead level) of 129 μg/L (normal range 0-99 μg/L) These two features have never been described in the previous medical literature on FR. Thus, we propose that examining the infiltrated cells in detail in histopathological studies and inspecting the levels of lead and other microelements in the blood may increase our understanding of the pathogenesis of FR.

Generation of bright attosecond x-ray pulse trains via Thomson scattering from laser-plasma accelerators

Generation of attosecond x-ray pulse attracts more and more attention within the advanced light source user community due to its potentially wide applications. Here we propose an all-optical scheme to generate bright, attosecond hard x-ray pulse trains by Thomson backscattering of similarly structured electron beams produced in a vacuum channel by a tightly focused laser pulse. Design parameters for a proof-of-concept experiment are presented and demonstrated by using a particle-in-cell code and a four-dimensional laser-Compton scattering simulation code to model both the laser-based electron acceleration and Thomson scattering processes. Trains of 200 attosecond duration hard x-ray pulses holding stable longitudinal spacing with photon energies approaching 50 keV and maximum achievable peak brightness up to 10²⁰ photons/s/mm²/mrad²/0.1%BW for each micro-bunch are observed. The suggested physical scheme for attosecond x-ray pulse trains generation may directly access the fastest time scales relevant to electron dynamics in atoms, molecules and materials.

Electron density compression and oscillating effects on laser energy absorption in overdense plasma targets

An analytical model for energy absorption during the interaction of an ultrashort, ultraintense laser with an overdense plasma is proposed. Both the compression effect of the electron density profile and the oscillation of the electron plasma surface are self-consistently included, which exhibit significant influences on the laser energy absorption. Based on our model, the general scaling law of the compression effect depending on laser strength and initial density is derived, and the temporal variation of the laser absorption due to the boundary oscillating effect is presented. It is found that due to the oscillation of the electron plasma surface, the laser absorption rate will vibrate periodically at ω or 2ω frequency for the p-polarized and s-polarized laser, respectively. The effect of plasma collision on the laser absorption has also been investigated, which shows a considerable rise in absorption with increasing electron-ion collision frequency for both polarizations.

AKR1B10, a good prognostic indicator in gastric cancer

BACKGROUND AND OBJECTIVES

The aim of the study was to investigate the correlation between AKR1B10 expression and clinicopathological features of gastric cancer (GC).

METHODS

Real-time polymerase chain reaction (RT-PCR) was performed to determine AKR1B10 mRNA expression. AKR1B10 protein levels were measured by immunohistochemistry.

RESULTS

RT-PCR analysis confirmed that AKR1B10 was significantly down-regulated in gastric cancer compared with paired, normal mucosa. Immunohistochemistry revealed that the percentage of AKR1B10-positive specimens was lower in gastric carcinoma compared with normal specimens. The frequency of AKR1B10-positive GC specimens was higher in patients with tumor size <5 cm, no lymph node metastasis, no distant metastasis and lower tumor stages The mean survival time for patients in the AKR1B10-positive group was significantly higher compared with the AKR1B1-negative group. The 5-year survival rate for the AKR1B10-positive group was also significantly higher than for the AKR1B1-negative group. Cox regression analysis revealed that AKR1B10 expression is an independent prognostic factor of GC.

CONCLUSIONS

Expression of AKR1B10 in gastric cancer was significantly associated with tumor size, lymph node metastasis, distance metastasis and TNM stage, and AKR1B10 may be a good prognostic indicator in gastric cancer.

The luminescence properties of Bi(3+) sensitized Gd2MoO6:RE(3+) (RE=Eu or Sm) phosphors for solar spectral conversion

Gd2MoO6:RE(3+) (RE=Eu or Sm) and Gd2MoO6:Bi(3+), RE(3+) (RE=Eu or Sm) phosphors have been synthesized by combustion method. The samples are characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), photoluminescence excitation (PLE) and photoluminescence (PL) spectra. By introducing Bi(3+) ions into Gd2MoO6:RE(3+) (RE=Eu or Sm) phosphors, the excitation bands of Eu(3+) and Sm(3+) ions are broadened and shifted to short wavelength, meanwhile, the emission intensity are enhanced obviously. The energy transfer from Bi(3+) to the activators of Eu(3+) or Sm(3+) is observed and discussed. In addition, the process of ultraviolet light (250-400nm) converted into visible light can be achieved by using Gd2MoO6:Bi(3+), RE(3+) (RE=Eu or Sm) phosphor. These phosphors can be a promising ultraviolet-absorbing luminescent converter to enhance the photoelectrical conversion efficiency of dye-sensitized solar cells (DSSCs).