Microwave photonic comb filter with ultra-fast tunability

A microwave comb filter with ultra-fast tunability is proposed based on the fundamental delay-line microwave photonic filter. The central frequency of the passband or stopband in such a filter can be rapidly adjusted, along with the independent tunability of the free spectral range (FSR). Experimental results show that the central frequency of the transfer function is electronically tuned with a frequency difference of half of the FSR at a speed of <100  ps. Such high-speed tunability is vital for high-speed microwave switching, frequency hopping, cognitive radio, and next-generation radar systems.

A new small molecule inhibits Streptococcus mutans biofilms in vitro and in vivo

AIMS

The aim of this study was to identify new small molecules that can inhibit Streptococcus mutans biofilms by in vitro and in vivo model.

METHODS AND RESULTS

We evaluated the effect of a small molecule 2-amino-imidazole/triazole conjugate (2-AI/T) on the formation of Strep. mutans biofilms by culturing in 96-well plates. Toxicity was assessed through cell culture and intragastrically administering to mice. The anti-biofilm and anti-caries effects were investigated in vivo. The inhibitive mechanism was detected by isobaric tag for relative and absolute quantification (itraq) and RT-QPCR. In vitro and in vivo study revealed that 2-AI/T significantly inhibited biofilm formation of Strep. mutans and is more so than inhibiting planktonic cells without toxicity. The ribosome and histidine metabolism pathways of Strep. mutans were significantly regulated by this compound.

CONCLUSIONS

These results suggest that the 2-AI/T conjugate is a potent inhibitor that can be potentially developed into a new drug to treat and prevent dental caries.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first study to use small molecule from marine natural products, to protect from dental caries in vivo. It has potential broad range application in clinical caries prevention, or as a bioactive ingredient for food applications.

Exploring the Value of Using Color-Coded Quantitative DSA Evaluation on Bilateral Common Carotid Arteries in Predicting the Reliability of Intra-Ascending Aorta Flat Detector CT-CBV Maps

BACKGROUND AND PURPOSE

Cerebral blood volume, acquired with flat panel detector CT by injecting contrast medium into the ascending aorta, enabled real-time acquisition of brain functional information with remarkable reduction of contrast medium usage comparing to an intravenous injection approach. However, individual vasculature and flow variations cause inhomogeneous contrast medium distribution and unexpected asymmetric perfusion for certain patients even without cerebral circulatory disorders. This work aimed at testing the feasibility of using color-coded quantitative DSA to predict the reliability of flat panel detector CT-based CBV maps by injecting contrast medium into the ascending aorta by exploring the correlation between measurements of color-coded quantitative DSA and the symmetry of CBV maps.

MATERIALS AND METHODS

For 12 patients without perfusion-related cerebral abnormities, color-coded quantitative DSA at the aortic arch and flat panel detector CT-based CBV maps by injecting contrast medium into the ascending aorta were acquired. In color-coded quantitative DSA, ROIs were defined on the bilateral common carotid arteries. Time-density curves were extracted, and area under the curve values were calculated. To evaluate brain perfusion symmetry, we defined ROIs on the anterior and middle cerebral artery territories in CBV maps, and quantitative CBV values were extracted.

RESULTS

Eight patients demonstrated good perfusion symmetry with relative CBV of 0.96 ± 0.06, and their relative area under the curve was found to be 0.99 ± 0.02. For the other 4 patients, CBV from the left hemisphere was significantly lower than that from the right with relative CBV of 0.81 ± 0.09. This asymmetric perfusion was confirmed by the color-coded quantitative DSA with relative area under the curve values of 0.79 ± 0.03.

CONCLUSIONS

This preliminary study showed good correlation between relative area under the curve from color-coded quantitative DSA and relative CBV from CBV maps. Color-coded quantitative DSA potentially helped sort out patients whose vascular anatomy could support reliable CBV acquisitions of flat detector CT by injecting contrast medium into the ascending aorta.

17β-oestradiol enhances global DNA hypomethylation in CD4-positive T cells from female patients with lupus, through overexpression of oestrogen receptor-α-mediated downregulation of DNMT1

BACKGROUND

Systemic lupus erythematosus (SLE) affects primarily women, and oestrogen appears to play a significant role in SLE development. Our previous studies showed that inhibition of DNA methyltransferase 1 (DNMT1) enhanced global DNA hypomethylation in CD4+ T cells isolated from patients with SLE, and exacerbated SLE. However, the effects of 17β-oestradiol on global DNA hypomethylation and DNMT1 expression in CD4+ T cells of female patients with SLE remain largely unknown.

AIM

To investigate the ability of 17β-oestradiol to affect global DNA methylation in female SLE CD4+ T cells and the mechanism(s) underlying this ability.

METHODS

We enrolled 30 women with SLE and 15 controls. CD4+ T cells exposed to 17β-oestradiol were analysed by global DNA methylation measurements, western blotting and real-time PCR. Plasma 17β-oestradiol levels were measured by ELISA.

RESULTS

In female SLE CD4+ T cells, 17β-oestradiol downregulated DNMT1 expression at both the mRNA and protein levels, and enhanced global DNA hypomethylation. Plasma 17β-oestradiol levels were similar in patients with SLE and controls. The mRNA expression of oestrogen receptor (ER)α, but not of ERβ, was upregulated in SLE CD4+ T cells. Furthermore, the 17β-oestradiol-induced downregulation of DNMT1 expression and global DNA hypomethylation were rescued by an ER antagonist.

CONCLUSIONS

17β-oestradiol enhances global DNA hypomethylation in female SLE CD4+ T cells via downregulation of DNMT1 mediated by ERα overexpression.

In vitro antifungal susceptibility of Trichophyton violaceum isolated from tinea capitis patients

OBJECTIVES

Trichophyton violaceum is an anthropophilic dermatophyte that is endemic to parts of Africa and Asia and is sporadic in Europe. T. violaceum mainly causes tinea capitis in both children and adolescents. Although the infections caused by T. violaceum are of considerable medical importance, its antifungal susceptibility profile remains poorly examined.

METHODS

In this study, we tested the in vitro antifungal susceptibility of a set of clinical T. violaceum isolates obtained from tinea capitis patients, using the CLSI broth microdilution method. We tested eight antifungals and used isolates collected from Western China (21), Eastern China (12), the Middle East (1), Europe (20), South Africa (7) and Canada (1).

RESULTS

The geometric means of the MICs of the antifungals for all isolates were as follows (in increasing order): posaconazole, 0.021 mg/L; terbinafine, 0.023 mg/L; voriconazole, 0.062 mg/L; amphotericin B, 0.20 mg/L; itraconazole, 0.34 mg/L; caspofungin, 0.56 mg/L; fluconazole, 4.23 mg/L; and flucytosine, 8.46 mg/L. No statistically significant differences in the susceptibility profiles of T. violaceum were detected within the geographical regions tested.

CONCLUSIONS

Posaconazole, terbinafine and voriconazole were shown to be the most potent antifungal agents against T. violaceum isolates obtained from tinea capitis patients worldwide. These results might help clinicians in developing appropriate therapies that have a high probability of successfully treating tinea capitis due to T. violaceum.

Delayed-Onset Hearing Loss: Prevalence in Early School-Aged Children

Objectives:

(1) Demonstrate the prevalence rate of delayed-onset hearing loss in the early school-aged population for the academic year 2010-2011 in a single county of southeastern Michigan, and the state at large. (2) Describe the statewide hearing screening program used in the above population.

Methods:

Audiometric records of the Oakland County Health Department and the Michigan Department of Community Health for children participating in school-based hearing screening during academic year 2010-2011 were identified. Cross-sectional review of school-based hearing screening results of children in kindergarten, first, second, and fourth grades was performed. Failures were identified and audiograms analyzed confirming hearing loss type. In individuals with sensorineural loss, state newborn screening registries were queried to determine those with true delayed-onset. Demographics and degree of hearing loss on these individuals were collected. Prevalence using official state-level enrollment and census data was calculated.

Results:

A total of 46,501 children (~83% of grade-based cohort) participated in school-based hearing screening. Of the 1701 children who failed screening pure tone audiometry, 119 were found to have delayed-onset sensorineural or mixed hearing loss. Male predominance was slight (53%), and 46% had bilateral losses. Newborn hearing screening occurred in the first week of life in the majority (85%). A prevalence of 1.7 to 2.1 out of 1000 in Oakland County was calculated. Delayed-onset hearing loss is projected to have affected between 1325 and 1347 children in this grade cohort statewide during the study period.

Conclusions:

Delayed-onset hearing loss remains a not infrequent condition. School-aged hearing screening programs offer a valid mechanism to identify children with this condition.

In situ biaxial rotation at low-temperatures in high magnetic fields

We report the design, construction, and characterization of a biaxial sample rotation stage for use in a cryogenic system for orientation-dependent studies of anisotropic electronic transport phenomena at low temperatures and high magnetic fields. Our apparatus allows for continuous rotation of a sample about two axes, both independently and simultaneously.

Polarization-diversified photonic comb filter with independently tunable free spectrum range

A polarization-diversified photonic comb filter with tunable free spectrum range (FSR) is proposed using two variable differential group delay (DGD) elements in a loop configuration. Two different cosine transfer functions could be simultaneously realized on orthogonal polarization states. Experimental demonstrations also verify feasibilities in various reconfigurable transfer functions.

Associations of clinical features and prognosis with age at disease onset in patients with systemic lupus erythematosus

The objective of this study is to evaluate the association of clinical features and prognosis with age at disease onset in patients with systemic lupus erythematosus (SLE) in a large, multicenter Chinese cohort. Medical records of 1898 SLE inpatients from 15 hospitals were reviewed and classified into three groups according to their ages at disease presentation. Categorical data were analyzed by chi-square test and potentially associated factors were tested by multinomial logistic regression. Among the patients studied, 259 (13.6%) were juvenile onset (≤18 years), 1444 (76.1%) were early onset (>18 and ≤45 years) and 195 (10.3%) were late onset (>45 years). Whenever manifestations occurred, most patients (>80%) were diagnosed within two years. Juvenile-onset patients were more likely to be untreated before admission ( p < 0.001) and have mucocutaneous manifestations ( p < 0.001), but musculoskeletal symptoms ( p < 0.05) and leukopenia ( p < 0.05) were less frequent, while comorbidities were much higher in patients with late-onset SLE ( p < 0.001). Neuropsychiatric, cardiopulmonary, renal and gastrointestinal involvement, disease activity index and damage scores were similar among three groups. Anti-Sm antibodies were less prevalent in late-onset patients ( p < 0.05) and antimalarial drugs were more often applied to juvenile-onset patients ( p < 0.001). As expected, mortality was elevated in the late-onset SLE group ( p < 0.05), in which nearly half died of infections, which was much higher than those in the other two groups ( p < 0.001). Logistic regression confirmed that patients with juvenile- and early-onset disease were associated with high incidence of being untreated prior to admission, and with low incidence of comorbidities as well as deaths caused by infection compared to patients with late-onset lupus. Interestingly, our data showed that more patients with late-onset disease had a SLEDAI score change of >7 at discharge. In conclusion, age at onset has an impact on SLE disease status, and infection is the main cause of death in those with late-onset lupus. Considering that the late-onset patients had simultaneously easily controllable diseases and high incidence of comorbidities, a different treatment strategy from younger patients should be considered.

Magnetoplasmons in quasineutral epitaxial graphene nanoribbons

We present an infrared transmission spectroscopy study of the inter-Landau-level excitations in quasineutral epitaxial graphene nanoribbon arrays. We observed a substantial deviation in energy of the L(0(-1)) → L(1(0)) transition from the characteristic square root magnetic-field dependence of two-dimensional graphene. This deviation arises from the formation of an upper-hybrid mode between the Landau-level transition and the plasmon resonance. In the quantum regime, the hybrid mode exhibits a distinct dispersion relation, markedly different from that expected for conventional two-dimensional systems and highly doped graphene.

Feeding Artemisia annua alters digesta pH and muscle lipid oxidation products in broiler chickens

Because of growing consumer concern about the use of antimicrobials and the ban on most antibiotic feed additives in the European Union, there is increased interest in using alternatives to antimicrobials in poultry diets. Dried leaves of Artemisia annua have been used in Oriental medicine due to their antimicrobial activities. In the current study, the effect of including A. annua in broiler diets on hindgut and ceca pH, lipid oxidation products, and phenolic content of dark and white meat, and bird performance were investigated. A total of 96 broiler chicks were kept in 48 cages. Two cages with 2 birds per each cage are considered as 1 replicate, and there were 8 replications per treatment. The birds were fed corn-soy diets containing 0% (control), 2% (ART2), or 4% (ART4) dried A. annua leaves from d 14 through d 42. Cecal digesta pH was the lowest in birds fed the ART4 diet (P < 0.02), whereas the pH of ileal digesta was the lowest in ART2 (P < 0.01). Lipid oxidation products measured as TBA reactive substances (TBARS) were lower in the breast and thigh muscle of birds fed ART2 and ART4 diets compared with the control (P < 0.0001). No difference was found in total fat content of the liver, abdominal fat pads, or breast or thigh muscle content (P > 0.05). Artemisia annua addition did not affect final BW, weight gain, feed consumption, carcass weight, or feed:gain. No difference was observed in the relative weight of liver, abdominal fat, spleen, or heart tissue. Gastric acidity is protective against intestinal colonization and translocation of pathogenic bacteria. Therefore, gut pH and muscle tissue TBARS reduction in birds fed ART2 and ART4 suggest that A. annua may prove useful as a natural phytogenic feed additive with antioxidant potential that could be incorporated into poultry diets.

Development of genetically engineered TCR-transduced T cells for immunotherapy of chronic hepatitis B and C virus infections (P4222)

More than 350 million people worldwide are chronically infected with hepatitis B (HBV) or hepatitis C virus (HCV). While vigorous CD8 T cell responses are required to spontaneously clear acute HBV and HCV infections, these virus-specific T cells are typically diminished in number and functionally impaired in chronic HBV and HCV infections. Here, we set out to use adoptive therapy with TCR-engineered T cells to restore HBV and HCV-specific immune responses. Three HBV-specific and four HCV-specific TCRs with high avidity were cloned from patients and chimpanzees that cleared the respective infection, expressed in retroviral vectors and used to transduce lymphocytes of chimpanzees with chronic HBV and HCV infection. The transduced T cells gained a broad spectrum of antigen-specific effector functions (IFN-γ secretion, cytotoxicity and proliferation). They were expanded to high numbers via short-term anti-CD3 and IL-15/IL-21 stimulation, which resulted in a preservation of their differentiation status and a lower frequency of regulatory T cells than the conventional expansion method with anti-CD3 and IL-2. Collectively, we show that retroviral TCR gene transfer followed by short-term expansion in the presence of IL-15/IL-21 efficiently redirects the antigen specificity of resting primary T cells and generates a large number of functional effector T cells. These will be used in adoptive T cell therapy protocols to restore T cell function in chronic viral hepatitis.

Photonic generation of phase-coded microwave signals with tunable carrier frequency

A photonic scheme to generate a phase-coded microwave signal with tunable carrier frequency based on a simple single-trip and two-pass structure is proposed. Facilitated by the fiber Bragg grating and phase modulator along the trip, both frequency doubling and signal phase coding could be achieved simultaneously. Phase-coded microwave signals at 20 and 22 GHz are experimentally generated.

Photonic arbitrary waveform generation based on crossed frequency to time mapping

Microwave photonic arbitrary waveform generation based on incoherent frequency-to-time-mapping (FTTM) accompanied by intersymbol interference, so called crossed FTTM (CFTTM). The pulse shape can be defined and tuned by properly adjusting the spectrum shaper (symbol shape) and the degree of intersymbol interference. UWB-, triangular-, rectangle-, comb- and user-defined pulse shapes are experimentally obtained.

Peripheral blood CD40-CD40L expression in human breast cancer

BACKGROUND

Breast cancer is the most common cancer in women. T cell-based immunotherapy for cancer has attracted much attention recently. CD40 and CD40L occupy an important position of specific immune response. In this paper, we want to study the role of co-stimulatory molecules CD40/CD40L and their clinical significance in peripheral blood of patients with breast cancer.

METHODS

Thirty breast cancer patients served as observation group, who were diagnosed as having infiltrating ductal breast cancer histopathologically, and 30 healthy as control group. Flow cytometric analysis was conducted to detect the expression of CD40 and CD40L on B and T lymphocytes in peripheral blood. The relationship between the CD40/CD40L expression levels and pathological grades was analyzed.

RESULTS

The expression levels of CD40/CD40L on B cells and T cells in breast cancer patients were significantly higher than those in the controls (all P < 0.001), and CD40/CD40L levels had a significant positive relationship with pathological grades (all P < 0.001).

CONCLUSIONS

The upregulated levels of co-stimulators CD40/CD40L on B cells and T cells may play an important role in the immune pathogenesis of breast cancer.

Laparoscopic versus open surgery for rectal cancer: a clinical comparative study

OBJECTIVE

To compare short-term surgical outcomes and long-term survival following laparoscopic or open resection for rectal cancer.

METHODS

A total of 381 patients undergoing laparoscopic surgery and 276 undergoing open surgery for curative resection of rectal cancer were included. Long-term survival and peri- and postoperative data were retrospectively reviewed from a prospectively-collected database.

RESULTS

Surgical groups were comparable regarding age, gender, tumour stage and preoperative comorbidities. Laparascopic surgery was associated with significantly longer duration of surgery, less intraoperative blood loss and fewer postoperative infections than open surgery. Patients who underwent laparoscopic resection had significantly earlier recovery of gastrointestinal function than those who underwent open surgery. There were no significant between-group differences in number of lymph nodes excised, specimen length or distal margin. The 3- and 5-year survival rates and overall survival were similar in the two groups, and survival was not influenced by tumour location.

CONCLUSION

Laparoscopic surgery can achieve the same oncological results as open resection in patients with rectal cancer, supporting its continued use in the management of this disease.

Bandwidth improvement for slow light using amplification characteristics of cascaded vertical-cavity surface-emitting lasers

A scheme to improve the bandwidth of slow light using cascaded vertical-cavity surface-emitting lasers (VCSELs) is proposed and experimentally demonstrated. In the scheme, a proper adjustment on the gain peaks of two cascaded VCSELs enables the generation of the desired composite gain spectrum, which has flat-top gain and delay profiles with enhanced peak values. By employing the improved gain and delay profiles in a slow light system, a large delay can be achieved within a wider bandwidth. In the experiment, by using two cascaded VCSELs, a tunable slow light up to 135 ps for a 5 Gbits/s pseudorandom binary sequence is demonstrated with relatively low signal distortion.