Prognostic value of the baseline magnetic resonance score in patients with acute posterior circulation ischaemic stroke after mechanical thrombectomy.

AIM: To investigate the prognostic value of the composite posterior circulation Acute Stroke Prognosis Early Computed tomography (CT) Score (ASPECTS)-Collaterals (pcASCO) score, which combines diffusion-weighted imaging (DWI) posterior circulation ASPECTS (pcASPECTS) and the magnetic resonance angiography (MRA)-collateral circulation score at baseline among patients with acute posterior circulation ischaemic stroke after mechanical thrombectomy. MATERIALS AND METHODS: Patients with acute posterior circulation ischaemic stroke who underwent mechanical thrombectomy were analysed retrospectively. The DWI-pcASPECTS and MRA-collateral circulation score before treatment and the modified Rankin Scale (mRS) at 90 days after treatment were used as the endpoints. An mRS ≤2 was defined as a good prognosis, and an mRS ≥3 was defined as a poor prognosis. Multivariate logistic regression was used to analyse independent predictors of functional outcome 90 days after mechanical thrombectomy. RESULTS: Mechanical thrombectomy was performed in 57 patients; 38 patients had a good prognosis, 19 patients had a poor prognosis, and 33 patients were successfully recanalised. Univariate logistic regression found that National Institute of Health Stroke Scale (NIHSS) score (OR: 1.18, p<0.001), pcASPECTS (OR: 1.91, p=0.028) and pcASCO score (OR: 0.51, p=0.001) were factors of good functional outcome. Receiver operating characteristic curve (ROC curve) analysis showed that the diagnostic efficiency of the NIHSS and pcASCO was better (AUC = 0.88, 0.83, p<0.05) than that of the pcASPECTS (AUC = 0.65). The prediction model was established by age, NIHSS, and pcASCO, and the diagnostic efficiency of the prediction model was better (AUC = 0.94). CONCLUSIONS: The composite MR-pcASCO score can be used as an important predictor of the prognosis of patients with acute posterior circulation ischaemic stroke after mechanical thrombectomy.

[Association between onset time of sepsis-associated acute kidney injury and clinical outcome in patients with sepsis].

Objective: To explore the relationship between the onset time of sepsis-associated acute kidney injury (SA-AKI) and adverse clinical outcomes. Methods: Data were derived from Beijing Acute Kidney Injure Trial (BAKIT) which investigated the epidemiology of acute kidney injury (AKI) in critically ill patients at 30 intensive care units (ICU) of 28 tertiary hospitals in Beijing from 1 March to 31 August 2012. Patients who were older than 18 years and diagnosed with sepsis and AKI, and expected to stay in ICU for at least 24 h were included in this study. A total of 653 patients were included in this study, 414 males and 239 females with a mean age of (68.2±17.0) years. According to the onset time of SA-AKI, patients were grouped into early AKI (E-AKI) (AKI occurred within 48 hours after ICU admission) and late AKI (L-AKI) (AKI occurred after 48 hours of ICU admission) group. The primary outcome was major adverse kidney events (MAKE), consisted of all-cause mortality, renal replacement therapy-dependence, and an inability to recover to 1.5 times of the baseline creatinine value up to 30 days. Multivariable logistic regression was used to investigate the association between the onset time of SA-AKI and clinical outcomes. Results: A total of 653 patients with SA-AKI were included, 423 (64.8%) patients developed E-AKI, 230 (35.2%) cases developed L-AKI, MAKE occurred in 405 (62.0%) cases, and 301 (46.1%) patients died in hospital. Compared with E-AKI group, L-AKI patients showed higher AKI 3 level rate [55.7%(128/230) vs 40.2%(170/423), P<0.001], incidence of MAKE [72.6%(167/230) vs 56.3%(238/423,P<0.001)] and hospital mortality [55.2%(127/230) vs 44.1%(174/423), P=0.001]. The risk of MAKE and in-hospital mortality in L-AKI group increased for 2.55-fold times (OR=3.55, 95%CI: 1.94-6.04) and 1.84-fold times (OR=2.84, 95%CI: 1.44-5.60) when compared with those in E-AKI, respectively (both P<0.05). Conclusion: Late timing onset of SA-AKI is associated with poor clinical outcomes.

[Dose-response association between fluid overload and hospital mortality in patients with sepsis].

Objective: To investigate dose-response associations between fluid overload (FO) and hospital mortality in patients with sepsis. Methods: The current cohort study was prospective and multicenter. Data were derived from the China Critical Care Sepsis Trial, which was conducted from January 2013 to August 2014. Patients aged≥18 years who were admitted to intensive care units (ICUs) for at least 3 days were included. Fluid input/output, fluid balance, fluid overload (FO), and maximum FO (MFO) were calculated during the first 3 days of ICU admission. The patients were divided into three groups based on MFO values: MFO<5%L/kg, MFO 5%-10%L/kg, and MFO≥10% L/kg. Kaplan-Meier analysis was used to predict time to death in hospital in the three groups. Associations between MFO and in-hospital mortality were evaluated via multivariable Cox regression models with restricted cubic splines. Results: A total of 2 070 patients were included in the study, of which 1 339 were male and 731 were female, and the mean age was (62.6±17.9) years. Of 696 (33.6%) who died in hospital, 968 (46.8%) were in the MFO<5%L/kg group, 530 (25.6%) were in the MFO 5%-10%L/kg group, and 572 (27.6%) were in the MFO≥10%L/kg group. Deceased patients had significantly higher fluid input than surviving patients during the first 3 days [7 642.0 (2 874.3, 13 639.5) ml vs. 5 738.0 (1 489.0, 7 153.5)ml], and lower fluid output [4 086.0 (1 367.0, 6 354.5) ml vs. 6 130.0 (2 046.0, 11 762.0) ml]. The cumulative survival rates in the three groups gradually decreased with length of ICU stay, and they were 74.9% (725/968) in the MFO<5% L/kg group, 67.7% (359/530) in the MFO 5%-10%L/kg group, and 51.6% (295/572) in the MFO≥10%L/kg group. Compared with the MFO<5%L/kg group, the MFO≥10%L/kg group had a 49% increased risk of inhospital mortality (HR=1.49, 95%CI 1.28-1.73). For each 1% L/kg increase in MFO, the risk of in-hospital mortality increased by 7% (HR=1.07, 95% CI 1.05-1.09). There was a"J-shaped"non-linear association between MFO and in-hospital mortality with a nadir of 4.1% L/kg. Conclusion: Higher and lower optimum fluid balance levels were associated with an increased risk of in-hospital mortality, as reflected by the observed J-shaped non-linear association between fluid overload and inhospital mortality.

[A case of stage â ¢ pneumoconiosis with large shadow by burr-like changes misdiagnosed as lung cancer].

Pneumoconiosis is characterized by chronic lung inflammation and fibrosis, and inflammation can promote pulmonary fibrosis, which in turn leads to pneumoconiosis. When a large shadow with a long diameter of not less than 2 cm and a short diameter of not less than 1 cm appears in the lung, it can be classified as stage Ⅲ pneumoconiosis. This paper reports a case of stage Ⅲ pneumoconiosis with a large shadow in the upper right lung accompanied by burr-like changes misdiagnosed as lung cancer by CT examination.When the large shadow lesions in patients with pneumoconiosis and lung cancer are difficult to distinguish on CT, an additional MRI examination, particularly T(2)W imaging sequence is useful sequence for identifying the two.

Visualization of Chiral Electronic Structure and Anomalous Optical Response in a Material with Chiral Charge Density Waves.

Chiral materials have attracted significant research interests as they exhibit intriguing physical properties, such as chiral optical response, spin-momentum locking, and chiral induced spin selectivity. Recently, layered transition metal dichalcogenide 1T-TaS_{2} has been found to host a chiral charge density wave (CDW) order. Nevertheless, the physical consequences of the chiral order, for example, in electronic structures and the optical properties, are yet to be explored. Here, we report the spectroscopic visualization of an emergent chiral electronic band structure in the CDW phase, characterized by windmill-shaped Fermi surfaces. We uncover a remarkable chirality-dependent circularly polarized Raman response due to the salient in-plane chiral symmetry of CDW, although the ordinary circular dichroism vanishes. Chiral Fermi surfaces and anomalous Raman responses coincide with the CDW transition, proving their lattice origin. Our Letter paves a path to manipulate the chiral electronic and optical properties in two-dimensional materials and explore applications in polarization optics and spintronics.

Dynamic changes of bacteria communities in Moutai-flavour Daqu during storage analysed by next generation sequencing.

The quality of Moutai-flavour Baijiu is highly dependent on Moutai-flavour Daqu (MTDQ), which needs to be stored for 6 months before using. It brings abundant bacterium, which can metabolize various enzymes and favour compounds. But the reasonable storage time of MTDQ prepared in different seasons is still uncertain. To this end, the study revealed a detailed bacterial profile of storage MTDQ prepared in three different seasons (specifically, they were stored start from spring, summer and autumn) by using high-throughput sequencing approach (next generation sequencing). Results showed that major phyla of storage MTDQ were Firmicutes, Proteobacteria, Actinobacteria, Bacteroidetes and Fusobacteria. The advantages of Firmicutes were Thermoactinomyces and Bacillaceae. Significant differences in bacterial community structures of MTDQ from different seasons and storage time were observed. Compared with summer and autumn MTDQ, the decrease of Thermoactinomyces and increase of Desmospora in spring MTDQ were the main differences and bacterial community structures of summer and autumn MTDQ were more similar. The variation trends of the bacteria community indicated that the effective time of storage period was appropriately 6 months for spring MTDQ, 2 months for summer MTDQ and more than 6 months for autumn MTDQ. These results showed that the length of storage time was associated with the season and it is reasonable to adjust the storage time of MTDQ with the season.

[Association between fluid balance and clinical outcomes in sepsis patients with identified subtypes].

Objective: To identify clinical subphenotypes of sepsis by clinical variables, and the association between fluid balance (FB) and outcomes in sepsis patients with different subphenotypes. Methods: Data were derived from China Critical Care Sepsis Trial. A total of 2 075 patients were included in the study, with a mean age of (62.5±17.4) years, 1 362 (65.6%) were male, 713 (34.3%) were female. In-hospital mortality was the primary outcome. Clinical variables were entered into the latent profile analysis (LPA) model which was used to identify the subphenotypes of sepsis. Multivariable logistic regression model was used to explore the association of FB on the first 2 days admitted to ICU and in-hospital mortality. Results: Total of 687 (33.1%) patients died in the hospital. Four subphenotypes of sepsis were identified by the PLA model: 1 421 (68.5%) patients were identified as profile 1, which was characterized by the lowest in-hospital mortality (28.3%, 402/1 421) and was considered as the baseline subphenotype; profile 2 was characterized by multiple organ dysfunction(232, 11.2%); profile 3 was characterized by respiratory dysfunction (196, 9.4%) and profile 4 was characterized by kidney injury/failure (226, 10.9%). Profile 2 showed the highest in-hospital mortality (54.3%, 126/232), followed by profile 4 (39.4%, 89/226), profile 3 (35.7%, 70/196). Profile 2 had the highest FB of 68.5(34.7, 89.4)ml/kg on day 1 and decreased rapidly to 29.4(13.6, 49.8) ml/kg on day 2. Multivariable analysis showed that for every 10 ml/kg of FB increased on the first 48 hours admitted to ICU, the risk of in-hospital mortality decreased 14% (OR=0.86, 95%CI: 0.81-0.97) in profile 2, and increased 4% (OR=1.04, 95%CI:1.02-1.07) in profile 4. However, there were no significant association between FB on the fist 2 days admitted to ICU and the risk of in-hospital mortality in profile 1 (OR=1.06, 95%CI: 0.94-1.19)and in profile 3 (OR=0.99, 95%CI: 0.94-1.05). Conclusions: Four subphenotypes of sepsis were identified according to the clinical variables, which showed different characteristics, distributions, outcomes and responses to fluid balance.

Long non-coding RNA XIST protects chondrocytes ATDC5 and CHON-001 from IL-1ß-induced injury via regulating miR-653-5p/SIRT1 axis.

Chondrocyte apoptosis is linked to cartilage degeneration, and considered as a crucial event during the development of osteoarthritis (OA). X inactive specific transcript (XIST) is an oncogenic long non-coding RNA (lncRNA). However, its role in the pathophysiological process of OA remains largely unknown. In this work, quantitative real-time reverse transcriptase PCR (qRT-PCR) was employed to measure the expression of XIST, miR-653-5p and sirtuin1 (SIRT1) mRNA in OA and normal cartilage tissues. Chondrocyte cell lines, CHON-001 and ATDC5, were treated with different doses of interleukin- 1ß (IL-1ß) to mimic the inflammatory environment of OA in vitro. Overexpression plasmids, microRNA (miRNA) mimics, miRNA inhibitors and small interfering RNAs (siRNAs) were constructed and transfected into CHON-001 and ATDC5 cells. 3-(4,5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay was adopted to determine the cell viability. Western blot was used to detect the expression of apoptosis-related proteins. Enzyme-linked immunosorbent assay (ELISA) was employed to probe the expression levels of inflammatory factors. Flow cytometry was used to analyze the cell apoptosis. StarBase and TargetScan databases were used to predict the binding sites between XIST and miR-653-5p, miR-653-5p and 3'UTR of SIRT1, respectively, which were then verified by dual luciferase reporter assay. The data in the present study demonstrated that XIST and SIRT1 were down-regulated while miR-653-5p was up-regulated in OA tissues and cell models. The up-regulation of XIST increased the viability of CHON-001 and ATDC5 cells, while it impeded their apoptosis and inflammatory response induced by IL-1ß. Conversely, miR-653-5p had opposite effects. It was proved that miR-653-5p could be sponged and suppressed by XIST. Additionally, SIRT1 was identified as a target of miR-653-5p, and SIRT1 could be suppressed by XIST indirectly. In conclusion, down-regulated XIST was involved in the injury of chondrocytes during the pathophysiological process of OA, and XIST up-regulation protected chondrocytes from inflammatory injury via regulating miR-653-5p/SIRT1 axis.

Exploiting dimensionality and defect mitigation to create tunable microwave dielectrics.

The miniaturization and integration of frequency-agile microwave circuits--relevant to electronically tunable filters, antennas, resonators and phase shifters--with microelectronics offers tantalizing device possibilities, yet requires thin films whose dielectric constant at gigahertz frequencies can be tuned by applying a quasi-static electric field. Appropriate systems such as BaxSr1-xTiO3 have a paraelectric-ferroelectric transition just below ambient temperature, providing high tunability. Unfortunately, such films suffer significant losses arising from defects. Recognizing that progress is stymied by dielectric loss, we start with a system with exceptionally low loss--Srn+1TinO3n+1 phases--in which (SrO)2 crystallographic shear planes provide an alternative to the formation of point defects for accommodating non-stoichiometry. Here we report the experimental realization of a highly tunable ground state arising from the emergence of a local ferroelectric instability in biaxially strained Srn+1TinO3n+1 phases with n ≥ 3 at frequencies up to 125 GHz. In contrast to traditional methods of modifying ferroelectrics-doping or strain-in this unique system an increase in the separation between the (SrO)2 planes, which can be achieved by changing n, bolsters the local ferroelectric instability. This new control parameter, n, can be exploited to achieve a figure of merit at room temperature that rivals all known tunable microwave dielectrics.

[Regulation of m

N^(6)-methyladenosine (m^(6)A) has been identified as a conserved epitranscriptomic modification of eukaryotic mRNAs, and plays important biological roles in the regulation of cellular metabolic processes. However, its role in myogenic differentiation is unclear. Here, we altered the m^(6)A RNA methylation level by overexpression of METTL3, and explored the effect of m^(6)A RNA methylation on myogenic differentiation of murine myoblasts in vitro. The m6A RNA methylation level is regulated by exogenous methylation inhibitor cycloleucine (Cyc) and methyl donor betaine (Bet). Therefore, chemical reagents of Cyc and Bet were used to test the regulatory effect of m^(6)A RNA methylation on myogenic differentiation. Results showed that METTL3 and Bet positively regulated the m^(6)A RNA methylation levels, and Cyc negatively regulated m^(6)A RNA methylation levels. In addition, m^(6)A methylation positively regulated myogenic differentiation in murine myoblasts. These findings provide insight in the mechanisms underlying the effect of m^(6)A RNA methylation on myogenesis.

Terahertz rare-earth orthoferrite metamaterials by 3-D direct writing technology.

Terahertz (THz) radiation excites electronic and optical modes of many materials, and controlling interaction of these materials with THz pulses provides a fascinating avenue to achieve unprecedented functionalities in return. Here, woodpile-structured rare-earth orthoferrite metamaterials built with 3-D direct ink writing technology are proposed and experimentally demonstrated. Polarization-independent THz refraction and switching of resonances by varying the number of layers in the structure, as well as the structural parameters and specimen support angle are achieved. Such all-rare-earth-orthoferrite dielectric metamaterials are easy to fabricate and can be very promising in developing efficient and low cost THz functional metadevices.

Correlation of quantitative parameters of magnetic resonance perfusion-weighted imaging with vascular endothelial growth factor, microvessel density and hypoxia-inducible factor-1α in nasopharyngeal carcinoma: Evaluation on radiosensitivity study.

OBJECTIVES: To investigate the correlation of parameters of magnetic resonance perfusion-weighted imaging (MR-PWI) with the expression of vascular endothelial growth factor (VEGF), hypoxia-inducible factor-1α (HIF-1α) and microvessel density (MVD) in nasopharyngeal carcinoma (NPC) so as to explore the value of predicting radiosensitivity. DESIGN: A prospective study. SETTING: Department of Head-and-neck radiotherapy in Hunan Cancer Hospital. PARTICIPANTS: Ninety-four patients of NPC were included between December 2013 and December 2014. MAIN OUTCOME MEASURES: The expression of VEGF, MVD and HIF-1α was studied by immunohistochemistry, and magnetic resonance perfusion-weighted imaging (MR-PWI) was performed before and after undergoing radiotherapy (20 Gy dose). Parameters of MR-PWI, volume of primary tumour and rate of tumour remission were measured and calculated. Patients with primary local tumour were then divided into completely response group (CR group) and partially response group (non-CR group) according to tumour regression condition. Relevant parameters were analysed by Spearman, and diagnostic efficiency of radiosensitivity was analysed by receiver operating characteristic curve (ROC). RESULTS: The expression of VEGF was positively correlated with MVD (r = .322,P < .05), but the expression of HIF-1α was no significant correlations with VEGF and MVD. The expression VEGF was in positive correlation with fractional plasma volume (fpv) (r = .339, P = .05) before radiotherapy. There was a significant difference in the quantitative parameters of MR-PWI between CR group and non-CR group during the course of radiotherapy and at the end of radiotherapy treatment. The change of blood reflux constant (Δkep20) and extravascular extracellular space volume fraction (ΔVe20) before and after treatment was positively correlated with primary local tumour remission condition after 3 month treatment; Δkep and ΔVe were negatively correlated with primary local tumour remission condition after 3 months. Tumour regression rate was only positively correlated with Ve and the average volume of primary tumour after 2 week treatment (V1). ROC curve showed that R20 ≥ 65.69%, and was considered as a threshold to predict primary local tumour remission, with a sensitivity of 0.84 and specificity of 0.69, and area under the curve was 0.819 (P = .000). CONCLUSIONS: The parameters of MR-PWI with the expression of VEGF, HIF-1α and MVD could be guidance for predicting radiosensitivity in NPC.

Real-Time Observation of Phonon-Mediated σ-π Interband Scattering in MgB_{2}.

In systems having an anisotropic electronic structure, such as the layered materials graphite, graphene, and cuprates, impulsive light excitation can coherently stimulate specific bosonic modes, with exotic consequences for the emergent electronic properties. Here we show that the population of E_{2g} phonons in the multiband superconductor MgB_{2} can be selectively enhanced by femtosecond laser pulses, leading to a transient control of the number of carriers in the σ-electronic subsystem. The nonequilibrium evolution of the material optical constants is followed in the spectral region sensitive to both the a- and c-axis plasma frequencies and modeled theoretically, revealing the details of the σ-π interband scattering mechanism in MgB_{2}.

Surface Chemically Switchable Ultraviolet Luminescence from Interfacial Two-Dimensional Electron Gas.

We report intense, narrow line-width, surface chemisorption-activated and reversible ultraviolet (UV) photoluminescence from radiative recombination of the two-dimensional electron gas (2DEG) with photoexcited holes at LaAlO3/SrTiO3. The switchable luminescence arises from an electron transfer-driven modification of the electronic structure via H-chemisorption onto the AlO2-terminated surface of LaAlO3, at least 2 nm away from the interface. The control of the onset of emission and its intensity are functionalities that go beyond the luminescence of compound semiconductor quantum wells. Connections between reversible chemisorption, fast electron transfer, and quantum-well luminescence suggest a new model for surface chemically reconfigurable solid-state UV optoelectronics and molecular sensing.

[Research on the correlation and regulation of bone metabolism related biochemical indexes in different gestational ages].

Objective: To investigate the correlation and metabolic characteristics of the growth hormone (GH) and other bone metabolism related biochemical markers in pregnancy women serum. Methods: Determination of GH, 25 hydroxy vitamin D(25(OH)D), osteocalcin n-terminal fragments (N-MID), total propeptide of type 1 procollagen (TP1NP) and alkaline phosphatase (ALP) levels in different gestation women serum, the experimental group involving 75 cases of early pregnancy women(11-14 weeks), 135 cases of pregnancy women(15-21 weeks), 62 cases of late pregnancy women(31-40 weeks) and 28 cases of postpartum women(1-3 days). All cases were selected from prenatal screening patients in hospital from February 2016 to February 2017. The control group involving 55 cases of physically healthy nulliparous. The indicators of GH, 25(OH)D, TPINP and N-MID were detected by electrochemiluminescence and ALP were detected by rate method. All data were processed by SPSS. Variance analysis and Pearson correlation analysis were employed. Results: Serum GH level in early pregnancy, pregnancy, late pregnancy and control group were (4.54±2.26), (9.04±3.23), (20.16±4.89), (0.55±0.49)µg/L, respectively. The difference was statistically significant (F=270.037, P<0.01). Serum GH in each group of pregnant women were more higher than those in control group (all P<0.01), and there was statistical difference in different gestational stages(all P<0.01). Serum 25 (OH)D expression in early pregnancy, pregnancy and late pregnancy were (25.60±14.48), (27.10±12.05), (25.45±9.85)nmol/L. Compared with the control group(39.93±14.88)nmol/L, the difference was statistically significant (all P<0.01). Serum TP1NP level in early pregnancy, pregnancy, late pregnancy and control group were (44.44±11.80), (48.41±20.87), (102.63±41.73), (54.73±24.07)µg/L, respectively. The difference was significantly significant (F=54.027, P<0.01) and TP1NP in late pregnancy group was obvious higher than in early pregnancy group, pregnancy group and control group apart(all P<0.01). Serum N-MID level in early pregnancy, pregnancy, late pregnancy and control group were (5.91±2.64), (7.45±2.27), (17.24±6.47), (18.52±6.95)µg/L, and the difference was significantly significant(F=55.699, P<0.01). N-MID in early and middle pregnancy group were apparent lower than that in late pregnancy and control group (all P<0.01). Serum ALP level in early pregnancy, pregnancy, late pregnancy and control group were (49.74±10.14), (77.76±26.90), (168.34±45.15), (52.81±10.33) U/L, and the difference was significantly significant(F=180.349, P<0.01). However, there was noticeable difference in ALP level between late pregnancy and other pregnant group(P<0.01 or P<0.05). The serum GH, TP1NP and N-MID in postpartum women (1-3 days) were (1.44±0.99), (73.41±34.27), (12.10±5.64) µg/L, respectively. Compare with late pregnancy groups, the difference was significantly significant(all P<0.01). The content of GH in serum of 272 cases pregnant women was positively correlated with the concentration of TP1NP, N-MID and ALP, the gestational age and body weight of pregnant women(r=0.509, 0.720, 0.862, 0.827, 0.324, all P<0.01). The content of TP1NP, N-MID and ALP were positively correlated with gestational age, respectively(r=0.603, 0.722, 0.901, all P<0.01). Moreover, TP1NP expression was positively correlated with N-MID (r=0.849, P<0.01), and there was no correlation between other indexes. Conclusions: These findings have revealed that there are different metabolic character of the GH and bone metabolism related biochemical indexes during different pregnancy period. And there is a positive correlation between gestational age and the index of GH, N-MID, TP1NP, ALP, respectively. Finally, the bone metabolism is more active and Vitamin D deficiency is severe throughout pregnancy.

Current sensing using circularly birefringent twisted solid-core photonic crystal fiber.

Continuously twisted solid-core photonic crystal fiber (PCF) exhibits pure circular birefringence (optical activity), making it ideal for current sensors based on the Faraday effect. By numerical analysis, we identify the PCF geometry for which the circular birefringence (which scales linearly with twist rate) is a maximum. For silica-air PCF, this occurs at a shape parameter (diameter-to-spacing ratio of the hollow channels) of 0.37 and a scale parameter (spacing-to-wavelength) of 1.51. This result is confirmed experimentally by testing a range of different structures. To demonstrate the effectiveness of twisted PCF as a current sensor, a length of fiber is placed on the axis of a 7.6 cm long solenoid, and the Faraday rotation is measured at different values of dc current. The system is then used to chart the wavelength dependence of the Verdet constant.

[The epidemiology of bloodstream infections in Fuxing Hospital in 2012 in Beijing].

OBJECTIVE: To investigate the etiology, clinical features and outcome of hospitalized patients with bloodstream infections (BSIs) in a tertiary hospital. METHODS: Positive blood cultures were obtained from the microbiological laboratory in Fuxing Hospital, Capital Medical University from January 1, 2012 to December 31, 2012. BSIS events were identified and the epidemiology data were collected. RESULTS: A total of 149 patients and 154 BSIs events were confirmed by pathogenic and clinical evidence. The in-patients' BSIs rate was 0.8% in our hospital in 2012. According to the disease entities of the first BSIs onset, 15 patients (10.1%) were from surgical departments, 83 patients (55.7%) from the medical departments, and 51 patients (34.2%) from ICU. Thirty-three patients (22.1%) were diagnosed as septic shock. Sixty-eight patients died during hospital stay. The in-hospital mortality rate was 45.6%. Among the 154 BSIs events, 125 (81.2%) were nosocomial and 29 (18.8%) were community-acquired. A total of 188 strains were isolated from all BSIs, including 106 strains of (56.4%) gram-negative bacilli, 67 (35.6%) strains of gram-positive bacteria, and 15 (8.0%) strains of fungi. One hundred and fifty-nine strains of bacteria (84.6%)were isolated from 125 events of hospital-acquired BSIs. Twenty-six strains of bacteria were from catheter related bloodstream infections (CRBSIs). In gram-negative BSIs, there were more enterobacteriaceae in community-acquired BSIs. More non-fermentative bacteria were found in hospital-acquired BSIs than in community-acquired ones. The distribution of gram-negative bacilli was quite different between surgical departments, non-surgical departments and ICU (P=0.049). CONCLUSIONS: Pathogens of BSIs are quite different according to disease entities and where the patients are from. Local epidemiology of BSIs and distribution of related pathogens are helpful to physicians searching the optimal empirical antibiotics and improving the outcome.

[Correlation between red cell distribution width and the severity and prognosis of chronic thromboembolic pulmonary hypertension].

OBJECTIVE: To explore the relationship between circulating red cell distribution width (RDW) and the severity and prognosis of chronic thromboembolic pulmonary hypertension (CTEPH). METHODS: A total of 66 consecutive patients with very likely CTEPH diagnosed by echocardiography and/or right heart catheterization were enrolled from August, 2007 to July, 2014. The patients included 31 females and 35 males with a mean age of (58±13) years. Based on the cut-off value of RDW=14%, the patients were divided into 2 groups as RDW>14% group(n=21) and RDW≤14% group(n=45). The baseline profile was recorded and compared between the 2 groups and the follow-up outcomes were analyzed by ROC curves and Logistic regression survival analysis. RESULTS: The median of follow-up time was 2 years, including 21 dead and 45 survived patients. The RDW level was positively related to creatinine(r=0.258, P=0.037), BNP(r=0.263, P=0.033) and uric acid(r=0.359, P<0.010). ROC analysis showed that RDW, BNP, and uric acid were the effective predictors for all-cause mortality in CTEPH patients(P<0.001, P=0.038, respectively), the area under the curve being 0.734, 0.806, and 0.659 respectively. Based on the cut-off value of 14%, the sensitivity and specificity for RDW prediction for CTEPH mortality was 60% and 80% respectively. The RDW≤14% group had better prognosis than the RDW>14% group (P<0.001). Moreover, the levels of BNP and uric acid were higher in the RDW>14% group than those in the RDW≤14% group(U=-3.558, P<0.05). Multi-Logistic regression analysis showed that RDW>14% was an independent risk factor for predicting death in CTEPH patients. CONCLUSIONS: RDW level was inversely related to the clinical condition and prognosis of CTEPH. Higher RDW, as an independent risk factor for adverse events, was correlated with severity and worse prognosis of the disease.

Enhanced optical activity and circular dichroism in twisted photonic crystal fiber.

We demonstrate experimentally and theoretically that the core-guided mode in helically twisted photonic crystal fiber exhibits resonantly enhanced optical activity and circular dichroism in the vicinity of anti-crossings with leaky orbital angular momentum (OAM) modes in the cladding. This arises because the anti-crossings for left and right circularly polarized core modes occur at slightly different wavelengths.