Analysis and Design of a Polygonal Oblique Beam for the Butterfly Vibratory Gyroscope with Improved Robustness to Fabrication Imperfections

This paper focuses on structural optimization of a Butterfly vibratory gyroscope (BFVG). An oblique suspension beam adopting polygonal cross-section is proposed in order to enhance the sensitivity and robustness. The operation principles of the BFVG are introduced. The suspension beam, which was found to be the key component, is selectively stressed. Varying cross sections of the suspension beam, including parallelogram, pentagon, hexagon, platform of pentagon, L-shaped and convex shapes are compared with each other. In particular, in order to show the advantages of the proposed polygonal cross-section, the convex cross-section is used as a reference. The influence of fabrication imperfections, which includes alignment error, silicon thickness error, etching depth error, upper width error, bottom width error and deep reactive-ion etching (DRIE) verticality error, on the oblique beam's spindle azimuth angle of the two cross-sections is analyzed. Further, the quadrature error of two cross-sections with a fabrication defect is analyzed. The theoretical arithmetic results suggest that a polygonal cross-section beam is much more stable than a convex cross-section beam in most cases. The robustness of the fabrication imperfection is improved nine-fold and the quadrature error due to fabrication defect is reduced by 70 percent with a polygonal cross-section. It could be a better candidate for BFVG's oblique beam, which would provide a gyroscope with good robustness and repeatability.

A Dual-Butterfly Structure Gyroscope

This paper reports a dual-butterfly structure gyroscope based on the traditional butterfly structure. This novel structure is composed of two butterfly structures, each of which contains a main vibrational beam, four proof masses, and a coupling mechanism. The coupling mechanism in this proposed structure couples the two single butterfly structures and keeps the driving mode phases of the two single butterfly gyroscopes exactly opposite, increasing the double difference of traditional butterfly gyroscopes to a quad difference, which has the potential advantage of improving bias instability and g-sensitivity. The gyroscope was fabricated using a standard microfabrication method and tested in laboratory conditions. The experimental results show a Q-factor of 10,967 in driving mode and there were two peaks in the frequency responses curve of sensing direction due to unavoidable fabrication errors. Scale factor and bias instability were also measured, reaching a scale factor of 10.9 mV/°/s and a bias instability of 10.7°/h, according to the Allan Variance curve.

Role of proton-coupled folate transporter in pemetrexed resistance of mesothelioma: clinical evidence and new pharmacological tools

BACKGROUND

Thymidylate synthase (TS) has a predictive role in pemetrexed treatment of mesothelioma; however, additional chemoresistance mechanisms are poorly understood. Here, we explored the role of the reduced-folate carrier (RFC/SLC19A1) and proton-coupled folate transporter (PCFT/SLC46A1) in antifolate resistance in mesothelioma.

PATIENTS AND METHODS

PCFT, RFC and TS RNA and PCFT protein levels were determined by quantitative RT-PCR of frozen tissues and immunohistochemistry of tissue-microarrays, respectively, in two cohorts of pemetrexed-treated patients. Data were analyzed by t-test, Fisher's/log-rank test and Cox proportional models. The contribution of PCFT expression and PCFT-promoter methylation to pemetrexed activity were evaluated in mesothelioma cells and spheroids, through 5-aza-2'-deoxycytidine-mediated demethylation and siRNA-knockdown.

RESULTS

Pemetrexed-treated patients with low PCFT had significantly lower rates of disease control, and shorter overall survival (OS), in both the test (N = 73, 11.3 versus 20.1 months, P = 0.01) and validation (N = 51, 12.6 versus 30.3 months, P = 0.02) cohorts. Multivariate analysis confirmed PCFT-independent prognostic role. Low-PCFT protein levels were also associated with shorter OS. Patients with both low-PCFT and high-TS levels had the worst prognosis (OS, 5.5 months), whereas associations were neither found for RFC nor in pemetrexed-untreated patients. PCFT silencing reduced pemetrexed sensitivity, whereas 5-aza-2'-deoxycytidine overcame resistance.

CONCLUSIONS

These findings identify for the first time PCFT as a novel mesothelioma prognostic biomarker, prompting prospective trials for its validation. Moreover, preclinical data suggest that targeting PCFT-promoter methylation might eradicate pemetrexed-resistant cells characterized by low-PCFT expression.

A 4 mm² Double Differential Torsional MEMS Accelerometer Based on a Double-Beam Configuration

This paper reports the design and simulation of a 4 mm² double differential torsional MEMS accelerometer based on a double-beam configuration. Based on the structure of conventional torsional accelerometers, normally composed of one pair of proof masses and one torsional beam, this work explores the double differential configuration: a torsional accelerometer with two pairs of unbalanced proof masses rotating in reverse. Also, the torsional beam is designed as a double-beam structure, which is a symmetrical structure formed by two torsional beams separated by a certain distance. The device area of the novel accelerometer is more than 50 times smaller than that of a traditional double differential torsional MEMS accelerometer. The FEM simulation results demonstrate that the smaller device does not sacrifice other specifications, such as mechanical sensitivity, nonlinearity and temperature robustness. The mechanical sensitivity and nonlinearity of a ±15 g measuring range is 59.4 fF/g and 0.88%, respectively. Compared with traditional single-beam silicon structures, the novel structure can achieve lower maximum principle stress in critical regions and reduce the possibility of failure when high-g acceleration loading is applied along all three axes. The mechanical noise equivalent acceleration is about 0.13 mg/Hz in the theoretical calculations and the offset temperature coefficient is 0.25 mg/℃ in the full temperature range of −40 ℃ to 60 ℃.

[Long-term oncologic outcomes of localized high-risk prostate cancer undergoing brachytherapy combined with external-beam radiation therapy and maximal androgen blockade]

Objective: To investigate the oncologic outcome and PSA kinetics of localized high-risk prostate cancer (PCa) patients treated with combination strategy of radiation therapy (RT) and maximal androgen blockade (MAB). Methods: We retrospectively reviewed the clinical data of 320 localized PCa patients undergoing RT+ MAB from 2001 to 2015. And radiation treatment protocol consisted of permanent prostate brachytherapy (PPB) at 110 Gy and EBRT at 45 Gy/23 fractions. Results: The median follow-up time was 90 (range: 12-186) months. And 117 (36.6%) cases underwent MAB + external-beam radiotherapy (EBRT), and other 203 (63.4%) cases received MAB+ EBRT+ PPB. Multivariate Cox regression analyses showed that PSA kinetics were positive indicators of oncologic outcomes. Furthermore, PSA kinetics were aberrantly improved by supplemental PPB to MAB+ EBRT as following, PSA nadir (1.3±0.7)μg/L vs(0.11±0.06)μg/L, time of PSA decrease to nadir (7.5±1.8)months vs (3.2±2.1)months, PSA doubling time (15.6±4.2)months vs (22.6±6.1)months, PSA decreasing amplitude (84.6±6.2)%vs(95.8±3.4)%. Additionally, the median time of several important oncologic events in MAB+ EBRT+ PPB group were also prolonged than that in MAB+ EBRT group as following, overall survival (12.3 years vs 9.1 years, P<0.001), biochemical recurrence-free survival (9.8 years vs 6.5 years, P<0.001), skeletal-related event (10.4years vs 8.2 years, P<0.001), and cytotoxic chemotherapy (11.6 years vs 8.8 years, P=0.007). Conclusion: MAB+ EBRT+ PPB is extremely effective combination strategy for localized high-risk PCa patients, and PPB plays the important synergistic role in improving PSA kinetics, which are independent predictor for oncologic outcomes.

Eyelid and fornix reconstruction in abortive cryptophthalmos: a single-center experience over 12 years

PurposeAbortive cryptophthalmos is a rare congenital eyelid anomaly with poor prognosis for vision and cosmesis. The study aims to present its varied manifestations and surgical outcomes.Patients and methodsThe medical records of patients with abortive cryptophthalmos treated at the Oculoplastic Clinic of Beijing Tongren Hospital between January 2004 and May 2016 were reviewed. Early surgical intervention was performed when exposure keratopathy occurs. Upper eyelid and superior fornix were mainly reconstructed with sliding myocutaneous flap and scleral and amniotic grafts. Post-operative upper eyelid contour, recurrence of symblepharon, and ability to retain prosthesis were evaluated.ResultsThe study included 41 eyes of 28 patients. The median age at first presentation was 5 years (ranging from 1 month to 58 years). The majority (79%) with concurrent craniofacial abnormalities tended to be associated with more severe cryptophthalmos. Nine eyes of 9 patients had recurrence of symblepharon. Acceptable functional and cosmetic outcomes were achieved in 20 of the 24 patients receiving repair procedures during the follow-up period.ConclusionOne-stage reconstruction of eyelid and fornix with scleral and amniotic grafts is an effective strategy to correct abortive cryptophthalmos.

Pretreatment Predictors of Early Response Revealed by Quantitative Cerebral Blood Flow in Major Depressive Disorder

Objective

The potential pattern of regional cerebral blood flow (rCBF) in major depressive disorder (MDD) underlies different response to antidepressants medication remain unclear. This study aimed to investigate the differences of rCBF between patients with different treatment response.

Methods

Eighty MDD patients [(44 treatment-responsive depression (RD) and 36 non-responding depression (NRD)] and 42 healthy controls (HC) underwent pulsed arterial spin labeling (PASL) scans in magnetic resonance imaging and clinical estimates. The exact rCBF values of each groups were obtained via quantification evaluation.

Results

Compared to NRD, the RD patients showed decreased rCBF values in frontal sensorimotor network (i.e. left paracentral lobule, left medial frontal gyrus, right superior frontal gyrus and right middle frontal gyrus), and further receiver operating curve (ROC) analyses demonstrated that the altered rCBF in these four regions exhibited outstanding performance on distinguishing NRD from RD. The NRD also exhibited reduced rCBF in bilateral cerebellum posterior lobe and right middle occipital gyrus and elevated rCBF in right postcentral gyrus and right middle frontal gyrus as compared to HC.

Conclusions

The decreased rCBF in frontal sensorimotor network appeared to be distinct characteristics for NRD, and might be severed as promising neuroimaging markers to differentiate depressed patients with weak early response to antidepressant medication. These findings expand our understanding of neural substrate underlying the antidepressant efficacy.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Antisense locked nucleic acids targeting agrA inhibit quorum sensing and pathogenesis of community-associated methicillin-resistant Staphylococcus aureus

AIM

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is commonly associated with nonnosocomial skin and soft tissue infections due to its virulence, which is mainly controlled by the accessory gene regulator (agr) quorum sensing (QS) system. In this study (KFF)₃ K peptide-conjugated locked nucleic acids (PLNAs) targeting agrA mRNA were developed to inhibit agr activity and arrest the pathogenicity of CA-MRSA.

METHODS AND RESULTS

Two PLNAs were designed, and synthesized, after predicting the secondary structure of agrA mRNA. The influence on bacterial growth was tested using a growth curve assay. RT-qPCR, haemolysis assay, lactate dehydrogenase release assay and chemotaxis assay were used to evaluate the effects of the PLNAs on inhibiting agr QS. A mouse skin infection model was employed to test the protective effect of the PLNAs in vivo. None of the PLNAs were found to be bacteriostatic or bactericidal in vitro. However, one PLNA, PLNA34, showed strong ability to suppress expression of agrA and the effector molecule RNAIII in USA300 LAC strain. Furthermore, PLNA34 inhibited the expression of virulence genes that are upregulated by agr, including hla, psmα, psmβ and pvl. The haemolytic activity of the supernatants from PLNA34-treated bacteria was also dramatically reduced, as well as the capacity to lyse and recruit neutrophils. Moreover, PLNA34 showed high levels of protection in the CA-MRSA mouse skin infection model.

CONCLUSIONS

The anti-agrA PLNA34 can effectively inhibit the agr QS and suppress CA-MRSA pathogenicity.

SIGNIFICANCE AND IMPACT OF THE STUDY

agrA is a promising target for the development of antisense oligonucleotides to block agr QS.

Association analysis of imbalanced interhemispheric functional coordination and early therapeutic efficacy in major depressive disorder: Evidence from resting state fMRI

Introduction

Emerging evidences indicate that the alteration of interhemispheric functional coordination may be involved in the pathogenesis of major depressive disorder (MDD). In present study, we aim to explore the potential marker by using the voxel-mirrored homotopic connectivity (VMHC) approach, which may be contributing to predict the clinical prognosis in MDD.

Methods

Eighty-two MDD patients and 50 normal control (NC) subjects participated in this study. We divided the MDD group into unremitted and remitted group according to the reduction rate of Hamilton Rating Scale for Depression (HAMD) within 2 weeks.

Results

The study detected significantly decreased VMHC in bilateral precuneus (pCu), inferior temporal gyrus (ITG) and increased VMHC in middle frontal gyrus (MFG) and caudate nucleus when compared remitted depression (RD) group to unremitted depression (URD) group. Meanwhile, when compared with NC group, the URD group presented reduced VMHC in bilateral cerebellum anterior lobe, thalamus and postcentral gyrus. Furthermore, the VHMC in media frontal gyrus, postcentral gyrus and precentral gyrus were significantly decreased in RD group. Correlation analysis suggested that reduced VMHC in bilateral pCu was negatively correlated with the baseline HAMD score of URD (r = −0.325, P = 0.041). Receiver operating characteristic (ROC) curve indicated that three regional VMHC changes could identify depressed patient with poorer treatment response: ITG [area under curve (AUC) = 0.699, P = 0.002, 95% CI = 0.586–0.812], MFG (AUC = 0.692, P = 0.003, 95% CI = 0.580–0.805), pCu (AUC = 0.714, P = 0.001, 95% CI = 0.603–0.825).

Conclusion

The current study combined with previous evidence indicates that the subdued intrinsic interhemispheric functional connectivity might represents a novel neural trait involved in the pathophysiology of MDD.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Decreased interhemispheric functional coordination underlying the cognitive impairment in late-onset depression

Background

The intuitive association between cognitive dysfunction in late onset depression (LOD) and the aberrant functional activity in the brain's default-mode network (DMN) has prompted interest in exploring the role of the DMN in LOD. The altered pattern of resting state voxel-mirrored homotopic connectivity (VMHC) in cognitive processes is not yet well understood in LOD.

Methods

The study was designed to examine the implicit coupling between the alteration of interhemispheric functional coordination and cognitive impairment in LOD. Thirty-one LOD patients and 37 matched healthy controls (HC) underwent neuropsychological tests and functional magnetic resonance imaging (fMRI) in this study.

Results

Compared to HC group, attenuated VMHC in superior frontal gyrus, superior temporal gyrus, posterior cerebellar lobe, postcentral and precentral gyrus was observed in LOD. Neuro-behavioral relevancy approach revealed that the imbalanced interhemispheric functional coordination in bilateral cerebellum was positively correlated with the performance of trail making test in LOD (r = 0.367, P = 0.040).

Conclusion

Altered linkage pattern of intrinsic homotopic connectivity and cognition was firstly investigated in LOD, and it would provide a novel clue to reveal the neural substrates underlying the cognitive dysfunction in LOD.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Impact of cataract surgery on vision-related life performances: the usefulness of Real-Life Vision Test for cataract surgery outcomes evaluation

PURPOSE

Real-Life Vision Test (RLVT) is a newly developed performance-based measures of functional vision. This present study is designed to determine whether it could be a meaningful assessment for cataract surgery outcomes evaluation.

PATIENTS AND METHODS

Age-related cataract patients (56) who scheduled for bilateral cataract surgery and 44 age-matched controls were evaluated by four types of measurements: (1) demographic, medical, cognitive and depressive evaluation, and the reaction time testing; (2) clinical measures (visual acuity, contrast sensitivity, stereopsis, and color perception); (3) the 25-item National Eye Institute's Visual Functioning Questionnaire (NEI-VFQ); (4) the RLVT. Spearman's coefficients and multiple regression analysis were conducted to investigate the relationship among RLVT, clinical measures, and self-report assessment of visual function.

RESULTS

The results of RLVT, clinical measures, and NEI-VFQ total scores were improved significantly after cataract surgery. There were no differences between control subjects and post-surgery patients with respect to NEI-VFQ-25 total scores, self-rating depression scale scores and three tasks of RLVT. Change of RLVT was significantly associated with the change of clinical measures in the cataract group. Multiple regression analysis demonstrated that change of distance, intermediate, and near visual acuity, and binocular contrast sensitivity were significant predictors of improvements of RLVT.

CONCLUSIONS

Cataract surgery could improve real-world visual ability effectively for cataract patients. Our study highlights the potential usefulness of RLVT as an adjunct to the current outcomes evaluation system for cataract surgery. The use of RLVT combined with clinical and self-survey methods may be the comprehensive strategy to manifest the impact of cataract surgery on patients' overall vision-related quality of life.

Annexin A5 promotes macrophage activation and contributes to pulmonary fibrosis induced by silica particles

OBJECTIVE

To investigate the contributions and underlying molecular mechanisms of annexin A5 toward silica-induced pulmonary fibrosis.

METHODS

Male C57BL/6 mice were randomly divided into three groups and instilled intratracheally with silica, saline, or air. Mice were euthanized at 3, 7, 14, or 28 days following treatment. Annexin A5 levels in serum and lung tissues were detected by enzyme-linked immunosorbant assay (ELISA) assays or Western blots. The association of annexin A5 levels with silica-induced lung fibrosis was further investigated in the macrophage cell line, RAW264.7. Following exposure of these cells to silica at a concentration of 200 μg/ml for 6 or 12 h, the expression levels of transforming growth factor β1 (TGF-β1), interleukin 1α (IL-1α), Fas ligand (FasL), and their downstream targets were evaluated by Western blots. Furthermore, annexin A5 and FasL were knocked down by small interfering ribonucleic acid (siRNA) and TGF-β1 secretion into the cell culture medium was measured by ELISA assays or Western blots.

RESULTS

Mice treated with silica demonstrated lung fibrosis at 28 days following exposure, whereas, in controls, only mild and transient inflammation was evident at day 3 and day 7 postinstillation and was not present at day 14. Furthermore, silica-exposed mice exhibited significantly (p < 0.05) elevated levels of annexin A5 in serum and lung tissues, relative to control groups. Consistent with these findings, silica exposure of RAW264.7 cells for 6 or 12 h, led to an annexin A5-dependent increase in the expression levels of TGF-β1, IL-1α, FasL, and their downstream target molecules. These silica-induced changes were reversed by siRNA-mediated knockdown of annexin A5, but downregulation of FasL led to increased annexin A5 expression and reduced levels of TGF-β1, IL-1α, and FasL downstream target molecules.

CONCLUSIONS

These findings define a role of annexin A5 in promoting macrophage activation via Fas/FasL pathways in silica-induced lung fibrosis.

Multicomponent gas analysis using broadband quantum cascade laser spectroscopy

We present a broadband quantum cascade laser-based spectroscopic system covering the region between 850 and 1250 cm(-1). Its robust multipass cavity ensures a constant interaction length over the entire spectral region. The device enables the detection and identification of numerous molecules present in a complex gas mixture without any pre-treatment in two minutes. We demonstrate that we can detect sub-ppmv concentration of acetone in presence of 2% of water at the same wavenumber region.

Comparisons of egg quality traits, egg weight loss and hatchability between striped and normal duck eggs

1. The egg quality of striped and normal duck eggs was compared to determine why striped eggs show decreased hatchability. A total of 430 eggs, obtained from a Pekin duck breeder flock aged 50-65 wks, were used in three experiments. The eggs were weighed and assigned randomly to measure egg quality traits, egg weight (EW) loss and hatchability during incubation. 2. There were no significant differences between egg types in terms of egg shape index, eggshell strength and thickness, albumen height, Haugh unit, yolk colour, weight of the eggshell with or without membranes, calcium, phosphorus, copper and manganese contents in the eggshell (with the inner and outer membranes or without the inner membrane), albumen weight, dry matter of albumen, crude protein (CP) of thick albumen and pH of the thick albumen. 3. The weight of eggshells with membranes, weight of thick albumen and CP of thin albumen in striped eggs were lower than those in normal eggs. 4. The thin albumen in striped eggs was heavier than that in normal eggs. The pH of the thin albumin in striped egg was significantly higher than that in normal eggs. 5. There were no significant differences in EW loss during incubation or duckling weight between striped and normal eggs. However, the hatchability of striped eggs was lower. 6. The lower weight of the eggshell inner membrane and thick albumen, lower CP content and higher pH in the thin albumen of striped eggs might contribute to lower hatchability.

Development of the fetal cerebral cortex in the second trimester: assessment with 7T postmortem MR imaging

BACKGROUND AND PURPOSE

Few investigators have analyzed the fetal cerebral cortex with MR imaging of high magnetic strength. Our purpose was to document the sulcal development and obtain quantitative measurements of the fetal brain in the second trimester.

MATERIALS AND METHODS

The brains of 69 fetal specimens, with GA 12-22 weeks, were first scanned on a 7T MR imaging scanner. Then the sequential development of the different fissures and sulci was analyzed, and quantitative measurements of the cerebral cortex were obtained.

RESULTS

A new chronology of sulcal development during 12-22 weeks GA was summarized. Before 12 weeks, few sulci were present; by 16 weeks, many sulci were present. The 16th week could be considered the most intensive time point for sulcal emergence. Most sulci, except for the postcentral sulcus and intraparietal sulcus, were present by 22 weeks GA. Measurements of the fetal brains, each with different growth rates, linearly increased with GA, but no sexual dimorphisms or cerebral asymmetries were detected.

CONCLUSIONS

The second trimester is the most important phase, during which most sulci are present and can be clearly shown on 7T postmortem MR imaging. It is apparent that the specific time during which neuropathologic features of sulci appear, previously thought to be well understood, should be redefined. Quantitative data provide assistance in the precise understanding of the immature brain. The present results are valuable in anatomic education, research, and assessment of normal brain development in the uterus.

Gene expression profiling of Escherichia coli in response to interactions with the lettuce rhizosphere

AIMS

The objective of this study was to examine transcriptional changes in Escherichia coli when the bacterium was growing in the lettuce rhizoshpere.

METHODS AND RESULTS

A combination of microarray analyses, colonization assays and confocal microscopy was used to gain a more complete understanding of bacterial genes involved in the colonization and growth of E. coli K12 in the lettuce root rhizosphere using a novel hydroponic assay system. After 3 days of interaction with lettuce roots, E. coli genes involved in protein synthesis, stress responses and attachment were up-regulated. Mutants in curli production (crl, csgA) and flagella synthesis (fliN) had a reduced capacity to attach to roots as determined by bacterial counts and by confocal laser scanning microscopy.

CONCLUSIONS

This study indicates that E. coli K12 has the capability to colonize lettuce roots by using attachment genes and can readily adapt to the rhizosphere of lettuce plants.

SIGNIFICANCE AND IMPACT OF THE STUDY

Results of this study show curli production and biofilm modulation genes are important for rhizosphere colonization and may provide useful targets to disrupt this process. Further studies using pathogenic strains will provide additional information about lettuce-E. coli interactions.