Active wavefront shaping for controlling and improving multimode fi ber sensor

Wavefront shaping(WFS)techniques have been used as a powerful tool to control light propagation in complex media,including multimode fibers.In this paper,we propose a new application of WFS for multimode fber-based sensors.The use of a single multimode fiber alone,without any special fabrication,as a sensor based on the light intensity variations is not an easy task.The twist effect on multimode fiber is used as an example herein.Experimental results show that light intensity through the multimode fiber shows no direct relationship with the twist angle,but the correlation coefficient(CC)of speckle patterns does.Moreover,if WFS is applied to transform the spatially seemingly random light pattern at the exit of the multimode fiber into an optical focus.The focal pattern correlation and intensity both can serve to gauge the twist angle,with doubled measurement range and allowance of using a fast point detector to provide the feedback.With further development,WFS may find potentials to facilitate the development of multimode fber-based sensors in a variety of scenarios.

Styrene epoxidation catalyzed by polyoxometalate/quaternary ammonium phase transfer catalysts: The effect of cation size and catalyst deactivation mechanism

Catalytic epoxidation of alkenes is an important type of organic reaction in chemical industry,and the deep insight into catalyst deactivation will help to develop new epoxidation process.In this work,series of quaternary ammoniums bearing different cationic sizes,i.e.MTOA+(methyltrioctylammonium,[(C_(8)H_(17))_(3)CH_(3)N]+),HTMA+(hexadecyltrimethylammonium,[(C_(16)H_(33))(CH_(3))_(3)N]+) and DMDOA+(dimethyldioctadecylammonium,[(C_(18)H_(37))_(2)(CH_(3))_(2)N]+) were incorporated with polyoxometalate (POM) anions to prepare phase transfer catalysts (PTCs),which were used in the styrene epoxidations.Among them,(MTOA)_(3)PW_(4)O_(24)exhibits the best catalytic performance judged from the highest styrene conversion rate(52%) and styrene oxide selectivity (93%),during which the styrene epoxidation conditions were optimized.Meanwhile,the deactivation mechanism of this kind of PTCs was proposed firstly,i.e.in the case of low H_(2)O_(2) content,the oxidant can only be used in the styrene epoxidation,in which the catalyst can transform into stable Keggin-type POM.But when the content of H_(2)O_(2) is higher,the excess H_(2)O_(2) can reactivate the Keggin-type POM into active (PW_(4)O_(24))_(3)-anions,which can trigger the ring-opening polymerization of styrene oxide.Consequently,the catalyst is deactivated by adhered poly(styrene oxide)irreversibly,which was determined by NMR spectra.In this situation,the active moiety{PO_(4)[WO(O_(2))_(2)]_(4)}_(3)-in phase-transfer catalytic system can break into some unidentified species with low W/P ratio with the presence of epoxides.This work will be beneficial for the design of new PTCs in alkene epoxidation in fine chemical industry.

Sensitive Detection of Multiple Tumor Markers for Early Tumor Diagnosis

Tumor markers have a wide clinical applications for early tumor screening and diagnosis.In the study,the combined detection of serum tumor markers(SCC-Ag,CYFRA21-1,CEA,CA125,NSE)was used to explore the correlation and diagnostic efficacy of oral squamous cell carcinoma(OSCC).First,60 cases of OSCC patients,60 cases of patients with non-OSCC malignant tumors,and 60 cases of patients with healthy physical condition were collected as the control group in the People’s Hospital of Xinjiang Uygur Autonomous Region from January 2015 to January 2018.Each experimental subject were draw 2 mL of fasting peripheral blood,and the tumor markers of SCC-Ag,CYFRA21-1,CEA,CA125,and NSE concentration were detected in the blood respectively.The results showed that the levels of the 5 of serum tumor markers of OSCC patients were different with those of the non-OSCC malignant tumor group.Compared with the control group,there was a significant difference(P<0.05).And the results showed that the sensitivity,specificity,accuracy,and positive predictive values of CEA,CA125,SCC-Ag,CYFRA21-1,and NSE were significantly improved after combined detection.Therefore,the combined detection of the 5 tumor markers can be used for the early diagnosis of OSCC.

β-Arrestin-2 inhibits preference for alcohol in mice and suppresses Akt signaling in the dorsal striatum

In this study,we investigated the role ofβ-arrestin-2in alcohol preference using the two-bottle choice and conditioned place preference procedures in wild-type（WT）andβ-arrestin-2 knockout（KO）mice.Locomotion and righting reflex tests were performed to test alcohol sensitivity.The possible molecular signals regulated byβ-arrestin-2 were analyzed by Western blot.We found thatβ-arrestin-2 KO mice showed a marked increase in voluntary alcohol consumption without significant differences in preference for saccharin or aversion to quinine.These animals also exhibited higher conditioned place preference scores for alcohol than WT mice.Meanwhile,KO mice showed reduced sensitivity to alcohol and increased blood alcohol clearance.Furthermore,after the free consumption of alcohol,the activities of protein kinase B and glycogen synthase kinase 3β（GSK3β）increased in the dorsal striatum of WT mice,but not in KO mice,which showed high basal activity of Akt in the dorsal striatum.These results suggest thatβ-arrestin-2 negatively regulates alcohol preference and reward,likely through regulating the activation of signaling pathways including Akt/GSK3βin the dorsal striatum.

Anxiety-related cell-type-specific neural circuits in the anterior-dorsal bed nucleus of the stria terminalis

The bed nucleus of the stria terminalis(BNST) plays a critical role in regulating anxiety, yet the involved specific cell types and their connections functioning in anxiety-related behaviors remains elusive. Here we identified two cell subpopulations—corticotropin-releasing hormone-positive(CRH+) and protein kinase C-δ-positive(PKC-δ+) neurons—each displayed discrete emotionally valenced behaviors in the anterior-dorsal BNST(ad BNST). Using whole-cell patch-clamp recordings and virus-assisted circuit tracing techniques, we delineated the local and long-range connectivity networks in a cell-type-specific manner. The results show that the CRH+ and PKC-δ+ neurons received inputs from similar brain regions and exhibited significant differences in the downstream projection density. In addition, in vivo calcium imaging as well as gain-and loss-of-function studies characterized the physiological response properties and the functional heterogeneities in modulating anxiety, further suggesting the similarity and individuality between the two ad BNST cell types. These results provide novel insights into the circuit architecture of ad BNST neurons underlying the functionally specific neural pathways that relate to anxiety disorders.

The visible light-triggered nonvolatile memory performances in melamine-decorated <110>-oriented lead halide perovskites: A photo-responsive structural evolution insight

The exploration of novel photo/thermal-responsive nonvolatile memorizers will be beneficial for energysaving memories.Herein,new<110>-oriented perovskites using single template melamine,i.e.,[(MLAI-H_(2))(PbX_(4))]_n(X=Br (α-1),Cl (α-2),MLAI=melamine) have been prepared and their structures upon irradiation of visible light have been investigated.They have been fabricated as nonvolatile memory devices with structures of ITO/[(MLAI-H_(2))(PbX_(4))]_n/PMMA/Ag (device-1:X=Br,device-2:X=Cl),which can exhibit unique visible light-triggered binary nonvolatile memory performances.Interestingly,the silent or working status can be monitored by visible chromisms.Furthermore,the light-triggered binary resistive switching mechanisms of these ITO/[(MLAI-H_(2))(PbX_(4))]_n/PMMA/Ag memory devices have been clarified in terms of EPR,fluorescence,and single-crystal structural analysis.The presence of light-activated traps in<110>-oriented[(MLAI-H_(2))(PbX_(4))]_n perovskites are dominated in the appearance of light-triggered resistive switching behaviors,based on which the inverted internal electrical fields can be established.According to the structural analysis,the more distorted PbX_6octahedra,higher corrugated<110>-oriented perovskite sheets,and more condensed organic-inorganic packing in Br-containing perovskite are beneficial for the stabilization of light-activated traps,which lead to the better resistive switching behavior of device-1.This work can pave a new avenue for the establishment of novel energy-saving nonvolatile memorizers used in aerospace or military industries.

Neurocircuitry of Predatory Hunting

Predatory hunting is an important type of innate behavior evolutionarily conserved across the animal king-dom.It is typically composed of a set of sequential actions,including prey search,pursuit,attack,and consumption.This behavior is subject to control by the nervous system.Early studies used toads as a model to probe the neuroethology of hunting,which led to the proposal of a sensory-triggered release mechanism for hunting actions.More recent stud-ies have used genetically-trackable zebrafish and rodents and have made breakthrough discoveries in the neuroethol-ogy and neurocircuits underlying this behavior.Here,we review the sophisticated neurocircuitry involved in hunting and summarize the detailed mechanism for the circuitry to encode various aspects of hunting neuroethology,including sensory processing,sensorimotor transformation,motivation,and sequential encoding of hunting actions.We also discuss the overlapping brain circuits for hunting and feeding and point out the limitations of current studies.We propose that hunting is an ideal behavioral paradigm in which to study the neuroethology of motivated behaviors,which may shed new light on epidemic disorders,including bingeeating,obesity,and obsessive-compulsive disorders.