Posterior open wound healing in immediate implant placement using reactive soft tissue versus absorbable collagen sponge: a retrospective cohort study

The soft and hard tissue healing of open wounds in immediate implant placement are yet to be explored. The aim of this study was to compare the clinical outcomes of open wound healing using reactive soft tissue (RST) and absorbable collagen sponge (ACS). Forty implants placed immediately in posterior sockets were included; autologous RST was used in 20 and ACS substitute was used in 20. Soft tissue healing was primarily assessed through a novel scoring system and the evaluation of gingival recession. The horizontal bone width (HBW) and interproximal marginal bone level (MBL) were measured on radiographs to observe the hard tissue healing. No significant difference in total soft tissue healing score was observed at 2 weeks postoperatively. Notably, the ACS group showed better tissue colour (P = 0.016) but worse fibrous repair (P = 0.043) scores than the RST group. Gingival recession levels were comparable in the two groups, both before tooth extraction and after placement of the restoration. Regarding hard tissue, HBW and MBL changes showed no intergroup differences. Within the limitations of this study, both RST and ACS seemed effective for open wound closure, achieving ideal soft and hard tissue healing in immediate implant placement.

An Optical Fiber-Based Nanomotion Sensor for Rapid Antibiotic and Antifungal Susceptibility Tests

The emergence of antibiotic and antifungal resistant microorganisms represents nowadays a major public health issue that might push humanity into a post-antibiotic/antifungal era. One of the approaches to avoid such a catastrophe is to advance rapid antibiotic and antifungal susceptibility tests. In this study, we present a compact, optical fiber-based nanomotion sensor to achieve this goal by monitoring the dynamic nanoscale oscillation of a cantilever related to microorganism viability. High detection sensitivity was achieved that was attributed to the flexible two-photon polymerized cantilever with a spring constant of 0.3 N/m. This nanomotion device showed an excellent performance in the susceptibility tests of Escherichia coli and Candida albicans with a fast response in a time frame of minutes. As a proof-of-concept, with the simplicity of use and the potential of parallelization, our innovative sensor is anticipated to be an interesting candidate for future rapid antibiotic and antifungal susceptibility tests and other biomedical applications.

[Early brain imaging changes and its influence on electrode impedance after implantation of 3.0 T MRI-compatible deep brain stimulation system in Parkinson's disease subthalamic nucleus]

Objective: To analyze the imaging changes of in the early period after subthalamic nucleus (STN) deep brain stimulation (DBS) surgery for Parkinson's disease (PD) and its impact on electrode impedance by the application of 3.0T MRI-compatible devices. Methods: A retrospective analysis was performed for the data of 43 PD patients who underwent 3.0T MRI-compatible STN-DBS surgery from October 2022 to April 2023 at the First Affiliated Hospital of USTC(Anhui Provincial Hospital), including 27 males and 16 females, aged 43-68 (56±5) years. All patients underwent postoperative 3.0T MRI, CT scans,and impedance measurements 1 week postoperatively.Fifteen patients underwent 3.0T MRI and impedance measurements 1 month postoperatively. The differences in impedance of electrode contacts before and after the 3.0T MRI scans were compared. The occurrence of peri-lead cerebral edema (PLE) in patients was analyzed, as well as the differences in PLE detection rates between the two imaging methods, and the differences in the incidence and volume of PLE at different microelectrode recordings, the occurrence and detection of postoperative PLE, and different microelectrode recording (MER) times and different time nodes were compared. The correlation between electrode impedance and the volume of edema around the nucleus was analyzed. Results: All 43 patients successfully underwent surgery, with a total of 86 electrodes implanted. There was no significant difference in electrode impedance values before and after the 3.0T MRI examinations at 1 week and 1 month postoperatively. The PLE detection rate with 3.0T MRI was 95.12%(39/43), which is significantly higher than that of CT imaging 17.07% (7/43)(χ2=50.705, P<0.001). One week after surgery, the incidence and volume of PLE were higher in the multiple MER group compared with the single MER group, but the difference was not statistically significant. The volume of PLE [M(Q1, Q3) 0 (0, 1.211) cm3] at 1 month was significantly smaller than that at 1 week [0.243 (0, 2.914) cm3] (Z=-3.408, P=0.001). The impedance of electrode contacts within 1 month postoperatively showed a trend of initial decrease followed by an increase, which was negatively correlated with SE volume(r=-0.317, P=0.014). Conclusions: The application of 3.0T MRI-compatible DBS devices in the surgical treatment of PD patients improves the accuracy of early postoperative imaging assessment. The electrode impedance is more stable as the edema around the nucleus subsided at 1 month after surgery, which is suitable for the first program control.

[Analysis of complications and learning curve effects related to deep brain stimulation surgery in 822 Parkinson's disesase patients with the same surgeon]

Objective: To analyze the complications related to deep brain stimulation(DBS) surgery in Parkinson's disease(PD) patients and to determine whether there is a learning curve effect in terms of complications. Methods: Retrospective analysis of the DBS surgical data of 822 PD patients performed by the same surgeon at the First Affiliated Hospital of the University of Science and Technology of China (Anhui Provincial Hospital) from December 2012 to December 2022. The complications related to DBS were evaluated and analyzed the complications of every 100 DBS surgery were further analyzed. Results: A total of 822 PD patients, 453 males and 369 females, aged 31-80 years old, were included. The minimum follow-up period after DBS surgery is 6 months. Surgical related complications occurred in 55 patients (6.69%), including 5 patients (0.61%) with slight bleeding around the electrode, 1 patient (0.12%) with cerebral infarction, 4 patients (0.49%) with postoperative epilepsy, 42 patients (5.11%) with postoperative delirium, 2 patients (0.24%) with respiratory distress, and 1 patient (0.12%) with acute cardiac insufficiency. There were 16 cases (1.94%) of hardware related complications in DBS, of which 4 cases (0.48%) had infection, 1 case (0.12%) had a broken angle at the connection between the pulse generator and the extension wire, 8 cases (0.97%) had an excessively tight extension wire, and 3 cases (0.36%) had an IPG bag hematoma. In the infected cases, 2 patients removed IPG and extension wires. There were 7 cases (0.85%) of stimulus related complications, including 4 cases (0.61%) with programmed sensory abnormalities, 1 case (0.12%) with postoperative abnormal movements and dance like movements, and 2 cases (0.24%) with psychiatric symptoms. A comprehensive analysis was conducted on the above complications, among which 8 cases (0.97%) were relatively serious complications. After active treatment, satisfactory results were achieved, and none of them affected the patient's DBS treatment effect and no patients died. For every 100 cases of DBS surgery complications were analyzed, the percentage of complications decreased significantly from 14.50% (58 cases) in the first 400 cases to 4.73% (20 cases) in the last 400 cases (P<0.001). Conclusion: DBS surgery is safe and has an acceptable low incidence of complications. The incidence of complications also decreases with the accumulation of experience, showing a learning curve effect.

Constrained Model Predictive Control Based on Event Triggering for the Rare Earth Extraction Process

Since the reagent dosage is manually adjusted according to work conditions, an event-triggered constrained model predictive control is proposed for rare earth extraction. First, the linear predictive system, based on a state space model, is established. Subsequently, the feedback correction link is fine-tuned to reduce the prediction error. Following this, an objective optimization function, incorporating input and output constraints, is introduced to calculate the appropriate reagent dosage. Finally, an event-triggering mechanism, underpinned by a designated threshold, is designed to update the controller. Simulation outcomes substantiate the efficacy of the proposed approach.

Developmental and cardiac toxicity assessment of Ethyl 3-(N-butylacetamido) propanoate (EBAAP) in zebrafish embryos

Ethyl 3-(N-butylacetamido) propanoate (EBAAP) is one of the most widely used mosquito repellents worldwide, and is also commonly used to produce cosmetics. Residues have recently been detected in surface and groundwater in many countries, and their potential to harm the environment is unknown. Therefore, more studies are needed to fully assess the toxicity of EBAAP. This is the first investigation into the developmental toxicity and cardiotoxicity of EBAAP on zebrafish embryos. EBAAP was toxic to zebrafish, with a lethal concentration 50 (LC50) of 140 mg/L at 72 hours post fertilization (hpf). EBAAP exposure also reduced body length, slowed the yolk absorption rate, induced spinal curvature and pericardial edema, decreased heart rate, promoted linear lengthening of the heart, and diminished cardiac pumping ability. The expression of heart developmental-related genes (nkx2.5, myh6, tbx5a, vmhc, gata4, tbx2b) was dysregulated, intracellular oxidative stress increased significantly, the activities of catalase (CAT) and superoxide dismutase (SOD) decreased, and malondialdehyde (MDA) content increased significantly. The expression of apoptosis-related genes (bax/bcl2, p53, caspase9, caspase3) was significantly upregulated. In conclusion, EBAAP induced abnormal morphology and heart defects during the early stages of zebrafish embryo development by potentially inducing the generation and accumulation of reactive oxygen species (ROS) in vivo and activating the oxidative stress response. These events dysregulate the expression of several genes and activate endogenous apoptosis pathways, eventually leading to developmental disorders and heart defects.

Fiber Bragg gratings inscribed in nanobore fibers

The nanobore fiber (NBF) is a promising nanoscale optofluidic platform due to its long nanochannel and unique optical properties. However, so far, the applications of NBF have been based only on its original fiber geometry without any extra functionalities, in contrast with various telecom fiber devices, which may limit its wide applications. Here, we provide the first, to the best of our knowledge, demonstration of NBF-based fiber Bragg gratings (FBGs) introduced by either the femtosecond (fs) laser direct writing technique or the ultraviolet (UV) laser phase mask technique. Moreover, the FBG fabricated via the UV laser was optimized, achieving a high reflectivity of 96.89% and simultaneously preserving the open nanochannel. The NBF-based FBGs were characterized in terms of temperature variation and the infiltration of different liquids, and they showed high potential for nanofluidic applications.

Axonal damage and astrocytosis are biological correlates of grey matter network integrity loss: a cohort study in autosomal dominant Alzheimer disease

Brain development and maturation leads to grey matter networks that can be measured using magnetic resonance imaging. Network integrity is an indicator of information processing capacity which declines in neurodegenerative disorders such as Alzheimer disease (AD). The biological mechanisms causing this loss of network integrity remain unknown. Cerebrospinal fluid (CSF) protein biomarkers are available for studying diverse pathological mechanisms in humans and can provide insight into decline. We investigated the relationships between 10 CSF proteins and network integrity in mutation carriers (N=219) and noncarriers (N=136) of the Dominantly Inherited Alzheimer Network Observational study. Abnormalities in Aβ, Tau, synaptic (SNAP-25, neurogranin) and neuronal calcium-sensor protein (VILIP-1) preceded grey matter network disruptions by several years, while inflammation related (YKL-40) and axonal injury (NfL) abnormalities co-occurred and correlated with network integrity. This suggests that axonal loss and inflammation play a role in structural grey matter network changes.

Key points

Abnormal levels of fluid markers for neuronal damage and inflammatory processes in CSF are associated with grey matter network disruptions.The strongest association was with NfL, suggesting that axonal loss may contribute to disrupted network organization as observed in AD.Tracking biomarker trajectories over the disease course, changes in CSF biomarkers generally precede changes in brain networks by several years.

Ultralow-loss fusion splicing between antiresonant hollow-core fibers and antireflection-coated single-mode fibers with low return loss

The Fresnel reflection of a splice from the air-silica interface between a hollow-core fiber (HCF) and a solid-core conventional fiber will increase the splicing loss and also cause possible instability of transmission. Here, for the first time, we develop a novel approach to fusion splicing an antireflection-coated (AR-coated) conventional fiber and an antiresonant HCF, which was generally claimed to be impossible because of the heat-induced damage of the coating, and achieve state-of-the-art ultralow fusion splicing loss less than 0.3 dB and a low return loss less than -28 dB by optimizing the splicing procedures and parameters. Our new fusion splicing approach will benefit the wide application of HCFs in telecoms, laser technologies, gyroscopes, and fiber gas cells.

[Recombinant Schistosoma japonicum egg ribonuclease SjCP1412 inhibits the activation of LX-2 hepatic stellate cells in vitro]

OBJECTIVE

To investigate the effect of recombinant Schistosoma japonicum egg ribonuclease SjCP1412 (rSjCP1412) on proliferation, cell cycle, apoptosis and activation of human hepatic stellate cells LX-2 in vitro, and explore the underlying mechanisms.

METHODS

The rSjCP1412 protein was expressed in Escherichia coli BL21 by prokaryotic expression, and the highly purified soluble rSjCP1412 protein was prepared by Ni NTA affinity chromatography and urea gradient refolding dialysis. Yeast RNA was digested using 12.5, 25.0, 50.0 µg rSjCP1412 proteins at 37 °C for 2, 3, 4 h, and the enzymatic products were electrophoresed on 1.5% agarose gel to observe the RNAase activity of rSjCP1412 protein. The proliferation of LX-2 cells stimulated by different doses of rSjCP1412 protein for 48 hours was measured using CCK-8 assay, and the apoptosis of LX-2 cells stimulated by different doses of rSjCP1412 protein for 48 hours was detected using the Annexin V-FITC/PI double staining, while the percentage of LX-2 cells at G0/G1, S and G2/M phases of cell cycle following stimulation with different doses of rSjCP1412 protein for 48 h was detected by DAPI staining. The type I collagen, type III collagen and α-smooth muscle actin (α-SMA) mRNA expression was quantified using quantitative florescent real-time PCR (qPCR) assay and Western blotting at transcriptional and translational levels in LX-2 cells following stimulation with different doses of rSjCP1412 protein for 48 h, while soluble egg antigen (SEA) served a positive control and PBS without rSjCP1412 protein as a normal control in the above experiments. The expression of collagen I, α-SMA and Smad4 protein was determined using Western blotting in LX-2 cells following stimulation with rSjCP1412 protein, transforming growth factor-β1 (TGF-β1) alone or in combination, to examine the signaling for the effect of rSjCP1412 protein on LX-2 cells.

RESULTS

The rSjCP1412 protein was successfully expressed and the highly purified soluble rSjCP1412 protein was prepared, which had a RNase activity. Compared with the normal group, the survival rates of LX-2 cells significantly decreased post-treatment with 12.5, 25.0, 50.0 µg/mL rSjCP1412 protein and SEA for 48 h (F = 22.417 and 20.448, both P values < 0.05). The apoptotic rates of LX-2 cells significantly increased post-treatment with 12.5, 25.0, 50.0 µg/mL rSjCP1412 protein for 48 h (F = 11.350, P < 0.05), and treatment with 12.5, 25.0, 50.0 µg/mL rSjCP1412 protein for 48 h resulted in arrest of LX-2 cells in G0/G1 phase (F = 20.710, P < 0.05). Treatment with 12.5, 25.0, 50.0 µg/mL rSjCP1412 protein for 48 h caused a significant reduction in relative expression levels of collagen I (F = 11.340, P < 0.05), collagen III (F = 456.600, P < 0.05) and α-SMA mRNA (F = 23.100, P < 0.05) in LX-2 cells, and both rSjCP1412 protein and SEA treatment caused a significant reduction in collagen I (F = 1 302.000, P < 0.05), α-SMA (F = 49.750, P < 0.05) and Smad4 protein expression (F = 52.420, P < 0.05) in LX-2 cells. In addition, rSjCP1412 protein treatment inhibited collagen I (F = 66.290, P < 0.05), α-SMA (F = 31.300, P < 0.05) and Smad4 protein expression (F = 27.010, P < 0.05) in LX-2 cells activated by TGF-β1.

CONCLUSIONS

rSjCP1412 protein may induce apoptosis of LX-2 cells and inhibit proliferation, cell cycle and activation of LX-2 cells through down-regulating Smad4 signaling molecules.

Insight into the impacts and mechanisms of ketone stress on the antibiotic resistance in Escherichia coli

Accumulation of toxic organic has posed a substantial pressure on the proliferation of bacterial resistance. While aromatic organics have been demonstrated to enhance the antibiotic resistance in bacteria, no information is yet available on the effects of non-aromatic organics on the variations of bacterial resistance. Here, we investigated the effects of a typical ketone (i.e., methylisobutanone (MIBK)) on the variations of antibiotic resistance in Escherichia coli (E. coli). The results showed that the growth of resistant E. coli under environmental concentration of 50 μg/L MIBK was firstly inhibited as explained by the transient disruption in the cell membrane and then recovered possibly due to the reactive oxygen species. Exposure to 50 μg/L MIBK gradually raised the abundance of representative resistance gene (ampR) in E. coli. In contrast, the high concentration of 50 mg/L MIBK continuously inhibited the growth of resistant E. coli by disrupting cell membrane and notably promoted the proliferation of ampR through enhancing the horizontal transformation and up-regulating the expression of efflux pump gene. These findings provided the first evidence for the evolution of bacterial resistance in response to ketone organics.

A Conformational Variant of p53 (U-p53AZ) as Blood-Based Biomarker for the Prediction of the Onset of Symptomatic Alzheimer's Disease

BACKGROUND

Ongoing research seeks to identify blood-based biomarkers able to predict onset and progression of Alzheimer's disease (AD).

OBJECTIVE

The unfolded conformational variant of p53 (U-p53AZ), previously observed in AD individuals, was evaluated in plasma samples from individuals participating in the Australian Imaging, Biomarkers and Lifestyle (AIBL) cohort for diagnostic and prognostic assessment, validated on a neuropsychological-based diagnosis, over the course of six years.

DESIGN

Retrospective Longitudinal Prognostic biomarker study.

SETTING

Single-center study based on the AIBL cohort.

PARTICIPANTS

482 participants of the AIBL cohort, aged 60-85 years, without uncontrolled diabetes, vascular disease, severe depression or psychiatric illnesses.

MEASUREMENTS

The AlzoSure® Predict test, consisting of immunoprecipitation (IP) followed by liquid chromatography (LC) tandem mass spectrometry (MS/MS), was performed to quantify the AZ 284® peptide as readout of U-p53AZ and compared with an independent neuropsychological diagnosis. The amyloid load via amyloid β-positron emission tomography (Aβ-PET) and supporting clinical information were included where possible.

RESULTS

U-p53AZ diagnostic and prognostic performance was assessed in both time-independent and time-dependent (36, 72 and 90 months following initial sampling) analyses. Prognostic performance of Aβ-PET and survival analyses with different risk factors (gender, Aβ-PET and APOE ε4 allele status) were also performed. U-p53AZ differentiated neuropsychologically graded AD from non-AD samples, and its detection at intermediate/high levels precisely identified present and future symptomatic AD. In both time-independent and time-dependent prognostic analyses U-p53AZ achieved area under the curve (AUC) >98%, significantly higher than Aβ-PET AUCs (between 84% and 93%, P respectively <0.0001 and <0.001). As single factor, U-p53AZ could clearly determine the risk of AD neuropsychological diagnosis over time (low versus intermediate/high U-p53AZ hazard ratio=2.99). Proportional hazards regression analysis identified U-p53AZ levels as a major independent predictor of AD onset.

CONCLUSIONS

These findings support use of U-p53AZ as blood-based biomarker predicting whether individuals would reach neuropsychologically-defined AD within six years prior to AD diagnosis. Integration of U-p53AZ in screening processes could support refined participant stratification for interventional studies.

Antibiotic-resistant bacteria and antibiotic resistance genes in uranium mine: Distribution and influencing factors

Both heavy metals and radiation could affect the proliferation and dissemination of emerging antibiotic resistance pollutants. As an environmental medium rich in radioactive metals, the profile of antibiotic resistance in uranium mine remains largely unknown. A uranium mine in Guangdong province, China was selected to investigate the distribution and influencing factors of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) including intracellular ARGs (iARGs), adsorbed-extracellular ARGs (aeARGs), and free extracellular ARGs (feARGs). The result indicated that sulfonamide and tetracycline ARB could be generally detected in mining area with the absolute concentrations of 7.70 × 10²-5.18 × 10⁵ colony forming unit/g. The abundances of aeARGs in mine soil were significantly higher than those of iARGs (p < 0.05), highlighting the critical contribution of aeARGs to ARGs spread. The feARGs in mine drainage and its receiving river were abundant (3.38 × 10⁴-1.86 × 10⁷ copies/mL). ARB, aeARGs, and iARGs may correlate with nitrogen species and heavy metals (e.g., U and Mn), and feARGs presented a significant correlation with chemical oxygen demand (p < 0.05). These findings demonstrate the occurrence of ARB and ARGs in uranium mine for the first time, thereby contributing to the assessment and control of the ecological risk of antibiotic resistance in radioactive environments.

Carboxin can induce cardiotoxicity in zebrafish embryos

Carboxin is a heterocyclic systemic fungicide, mainly used to prevent and control grain smut and wheat rust. Although its mammalian toxicity has been reported, its toxicity to acute exposure to aquatic animals is unknown. In our study, we used zebrafish as aquatic organisms to study Carboxin toxicity. Carboxin can cause developmental toxicity and cardiotoxicity in zebrafish embryos. Histopathological staining of cardiac sections reveals structural changes in zebrafish hearts, and fluorescence quantitative PCR results shows the heart developmental genes mRNA expression levels were disrupted significantly. Besides, carboxin can also cause oxidative stress and reactive oxygen species (ROS) accumulation in zebrafish embryos. The accumulation of ROS causes mitochondrial damage, which is where ATP energy is produced. So ATPase activities and gene expression level were measured and significantly decreased after exposure to carboxin. From the confocal images, the number of blood cells in the heart were decreased significantly after carboxin exposure. Besides, Carboxin exposure can inhibit myocardial cell proliferation. These are all causes to the heart failure, eventually leading to embryos death.

A Wearable Breath Sensor Based on Fiber-Tip Microcantilever

Respiration rate is an essential vital sign that requires monitoring under various conditions, including in strong electromagnetic environments such as in magnetic resonance imaging systems. To provide an electromagnetically-immune breath-sensing system, we propose an all-fiber-optic wearable breath sensor based on a fiber-tip microcantilever. The microcantilever was fabricated on a fiber-tip by two-photon polymerization microfabrication based on femtosecond laser, so that a micro Fabry-Pérot (FP) interferometer was formed between the microcantilever and the end-face of the fiber. The cavity length of the micro FP interferometer was reduced as a result of the bending of the microcantilever induced by breath airflow. The signal of breath rate was rebuilt by detecting power variations of the FP interferometer reflected light and applying dynamic thresholds. The breath sensor achieved a high sensitivity of 0.8 nm/(m/s) by detecting the reflection spectrum upon applied flow velocities from 0.53 to 5.31 m/s. This sensor was also shown to have excellent thermal stability as its cross-sensitivity of airflow with respect to the temperature response was only 0.095 (m/s)/°C. When mounted inside a wearable surgical mask, the sensor demonstrated the capability to detect various breath patterns, including normal, fast, random, and deep breaths. We anticipate the proposed wearable breath sensor could be a useful and reliable tool for respiration rate monitoring.

Low-loss fusion splicing between spacing-mismatched multicore fibers

Multicore fibers (MCFs) offer a fascinating solution to the need to increase the fiber density and thus meet the exponentially growing demand for capacity in optical communication networks. Despite overwhelming research into MCFs, the desire for a general fusion splicing scheme between dissimilar MCFs remains unanswered. Here, we propose a tapering technique to reshape MCFs that includes both reverse-tapering and down-tapering schemes and can be exploited to tailor the core-to-core spacing and modify the modal property of MCFs. By matching both the spacing and the mode field diameter, we demonstrated a low-loss (0.18 ± 0.10 dB) and low-crosstalk (-68 ± 3 dB) fusion splice between two spacing-mismatched MCFs with a spacing difference of up to 26 μm. The proposed novel schemes are also suitable for splicing between MCFs with slightly different spacings and can provide a unique perspective for fabricating MCF devices and boosting various MCF applications.

In-Fiber Polymer Microdisk Resonator and Its Sensing Applications of Temperature and Humidity

We proposed and realized an all-in-fiber polymer microdisk whispering-gallery mode (WGM) resonator, which is composed of a nanoscale polymer waveguide in conjunction with a polymer microdisk. The resonator is manufactured by femtosecond laser-induced two-photon polymerization inside a single-mode optical fiber, and its transmission spectrum has been investigated theoretically and experimentally. The WGM resonance was excited successfully, exhibiting a high Q factor of 2.3 × 10³ at a resonant wavelength of 1416.6 nm. The temperature and humidity responses of the resonator were tested as examples of possible application. Temperature sensitivity of -96 pm/°C when the temperature increased from 25 to 60 °C and humidity sensitivity of 54 pm/%RH when the relative humidity increased from 30 to 90% were obtained. The proposed in-fiber microdisk resonator is highly suitable for detection of microorganisms, bacteria, and single molecules.

Fiber-tip polymer clamped-beam probe for high-sensitivity nanoforce measurements

Micromanipulation and biological, material science, and medical applications often require to control or measure the forces asserted on small objects. Here, we demonstrate for the first time the microprinting of a novel fiber-tip-polymer clamped-beam probe micro-force sensor for the examination of biological samples. The proposed sensor consists of two bases, a clamped beam, and a force-sensing probe, which were developed using a femtosecond-laser-induced two-photon polymerization (TPP) technique. Based on the finite element method (FEM), the static performance of the structure was simulated to provide the basis for the structural design. A miniature all-fiber micro-force sensor of this type exhibited an ultrahigh force sensitivity of 1.51 nm μN-1, a detection limit of 54.9 nN, and an unambiguous sensor measurement range of ~2.9 mN. The Young's modulus of polydimethylsiloxane, a butterfly feeler, and human hair were successfully measured with the proposed sensor. To the best of our knowledge, this fiber sensor has the smallest force-detection limit in direct contact mode reported to date, comparable to that of an atomic force microscope (AFM). This approach opens new avenues towards the realization of small-footprint AFMs that could be easily adapted for use in outside specialized laboratories. As such, we believe that this device will be beneficial for high-precision biomedical and material science examination, and the proposed fabrication method provides a new route for the next generation of research on complex fiber-integrated polymer devices.

Magnetic field sensor based on helical long-period fiber grating with a three-core optical fiber

A high sensitivity optical fiber magnetic field sensor is proposed and implemented by using a helical long-period fiber grating (HLPFG) based on a three-core fiber (TCF) bonded to a U-shaped aluminum (Al) wire. An electrical current flowing through the Al wire in a perpendicular magnetic field can generate Ampere force, which changes the distance between the two arms of the U-shaped Al wire. Thus, when the intensity and direction of the magnetic field change, the bending curvature of TCF-HLPFG bonded to the U-shaped Al wire varies with the change of Ampere force, which is represented as the shift of resonant wavelength in the spectrum. The as-fabricated sensor can respond to the magnetic field direction and the intensity with a range from -15 mT to 15 mT, and the measured sensitivity is 456.5 pm/mT with Al wire electrical current 1A. The proposed sensor has the advantages of low cost, nondestructive measurement method and ease manufacture, and is expected to be applied to weak magnetic field measurements.

In-Fiber BaTiO3 Microsphere Resonator for High-Sensitivity Temperature Measurement

A fiber optic whispering gallery mode (WGM) resonator was proposed and realized by integrating an inline polymer waveguide with a microsphere mounted on it. The polymer waveguide with a diameter of 1 μm was printed with femtosecond laser-assisted multiphoton polymerization in a section of a grooved hollow-core fiber, which was sandwiched between two single-mode fibers. Two WGW resonators assembled with microspheres of different sizes were prepared. The transmission spectra of those stimulated WGMs were investigated both in simulation and experimentally. The temperature response of the resonators was particularly studied, and a linear sensitivity of −593 pm/°C was achieved from 20 °C to 100 °C.

Fiber-Tip Polymer Microcantilever for Fast and Highly Sensitive Hydrogen Measurement

Hydrogen as an antioxidant gas has been widely used in the medical and biological fields for preventing cancer or treating inflammation. However, controlling the hydrogen concentration is crucial for practical use due to its explosive property when its volume concentration in air reaches the explosive limit (4%). In this work, a polymer-based microcantilever (μ-cantilever) hydrogen sensor located at the end of a fiber tip is proposed to detect the hydrogen concentration in medical and biological applications. The proposed sensor was developed using femtosecond laser-induced two-photon polymerization (TPP) to print the polymer μ-cantilever and magnetron sputtering to coat a palladium (Pd) film on the upper surface of the μ-cantilever. Such a device exhibits a high sensitivity, roughly -2 nm %^-1 when the hydrogen concentration rises from 0% to 4.5% (v/v) and a short response time, around 13.5 s at 4% (v/v), making it suitable for medical and environmental applications. In addition to providing an ultracompact optical solution for fast and highly sensitive hydrogen measurement, the polymer μ-cantilever fiber sensor can be used for diverse medical and biological sensing applications by replacing Pd with other functional materials.

3M™ Petrifilm™ Staph Express Count Plate Method for the Enumeration of Staphylococcus aureus in Selected Dairy Foods: Collaborative Study

The 3M™ Petrifilm™ Staph Express Count plate method was compared with AOAC Official Method 975.55 for the enumeration of Staphylococcus aureus in selected foods. Five foods—ice cream, raw milk, yogurt, whey powder, and cheese—were analyzed for S. aureus by 12 collaborating laboratories. For each food tested, the collaborators received 8 blind test samples consisting of a control sample, a low inoculation level, a medium inoculation level, and a medium inoculation level with background flora, each in duplicate. The mean log10 counts for the methods were comparable for all 5 foods. The repeatability and reproducibility variances of the 24 h Petrifilm Staph Express Count plate method were similar to those of the 72 h standard method.

P4363The predictive capacity of two- and three-dimensional echocardiography detected right ventricular strain in disease severity of pre-capillary pulmonary hypertension

Background

Pulmonary hypertension (PH) patients have poor prognosis due to progressive right ventricular (RV) dysfunction. As a low-cost and non-invasive tool, echocardiography is by far the most widely used technique to investigate the RV structure and function in PH patients. Recent studies showed that RV longitudinal strain (RVLS) measured by two- or three-dimensional echocardiography (2DE, 3DE) was correlated with RV function parameters and have the potential to predict the prognosis of PH patients. However, few studies have compared the value of 2DE- and 3DE- RVLS to predict disease severity of pre-capillary PH patients. Therefore, our study aims to compare the capacity of RVLS assessed by 3DE and 2DE in predicting disease severity of pre-capillary PH patients.

Methods

We consecutively enrolled 57 patients (18 males and 39 females, 35±13 years) with pre-capillary PH diagnosed by right heart catheterization in our center. Standard transthoracic echocardiography was performed in all participants. 2DE- RVLS were obtained from speckle-tracking analyses using GE EchoPAC version 201; while 3DE- RVLS were analyzed by TomTec 4D RV-Function 2.0. On the basis of the risk assessment strategy of 2015 ESC Guidelines for the diagnosis and treatment of pulmonary hypertension, all the participants were classified into low risk or intermediate-high risk groups. Linear regression analyses were performed to evaluate the correlations between RVLS and peak oxygen consumption (PVO2). In addition, receive operating characteristic curves (ROC) were used to compare the predictive values of 2DE- and 3DE-RVLS and identify the optimal cut points for the detection of low risk based on the risk assessment strategy of 2015 ESC Guidelines.

Results

Linear regression analyses showed a significant correlation between PVO2 and 2DE- RVLS (r=−0.484, P<0.001), while a relatively weaker correlation was observed between PVO2 and 3DE- RVLS (r=−0.299, P=0.024). ROC curve showed 2DE-RVEF had a better capacity to classify pre-capillary PH patients into low or intermediate-high risk groups (2DE- vs 3DE-: AUC=0.78, P=0.003 vs AUC=0.69, P=0.044). Optimal cut-offs found 2DE-RVEF <−13.85% had a 73.3% sensibility and 75.0% specificity to predict low risk.

Conclusions

Both two- and three-dimensional echocardiography detected RVLS had the potential to evaluate disease severity of pre-capillary PH patients, but the former may have a better predictive capacity.

Minimizing the Sample Sizes of Clinical Trials on Preclinical and Early Symptomatic Stage of Alzheimer Disease

BACKGROUND

Clinical trials of investigational drugs for Alzheimer disease (AD) increasingly focus on the prodromal (symptomatic) stage of the illness and now its preclinical (asymptomatic) stage. Sensitive and specific cognitive and functional endpoints are needed to track subtle cognitive and functional changes in the early and preclinical stages to minimize sample sizes in these trials.

OBJECTIVES

To identify informative items in a standard clinical assessment protocol and a psychometric battery that are predictive of onset of dementia symptom.

DESIGN

Longitudinal retrospective study.

SETTING

Washington University (WU) Knight Alzheimer Disease Research Center (ADRC).

PARTICIPANTS

A total of 735 individuals at least 65 years old and cognitively normal at baseline from a longitudinal clinical cohort at the WU Knight ADRC.

MEASUREMENTS

The annual clinical assessment included a wide spectrum of functional and cognitive domains; a comprehensive psychometric battery was completed about 2 weeks after the clinical evaluation. Psychometricians are blinded to the results of the clinical evaluation and to the prior performance of the participants on the psychometric tests.

RESULTS

The mean age at baseline of the 735 participants was 74.30 and 62.31% were female. 240 individuals developed prodromal dementia symptoms (consistent with mild cognitive impairment due to AD and with very mild AD dementia) during longitudinal follow-up (mean follow-up=6.79 years). Among a total of 562 items in the clinical and cognitive assessments under analysis, 292 (52%) were identified as informative because their longitudinal changes were predictive of symptomatic onset. When these items were used to form the functional and cognitive composites, the longitudinal rates of changes were free of a learning effect and captured subtle longitudinal progression prior to symptomatic onset. The rates of change were much greater right after the symptomatic onset than those from the functional and cognitive composites formed using non-informative items. Although the sample sizes for prevention trials (prior to symptomatic onset) using the informative items still yield large numbers, the sample sizes for early treatment trial (after symptomatic onset) was much smaller than those derived from all the items or from the non-informative items alone.

CONCLUSIONS

The antecedent longitudinal changes in nearly half of the items in a clinical assessment protocol and a comprehensive cognitive battery did not show statistically significant ability to predict the dementia symptom onset, and hence may be non-informative to track the preclinical functional and cognitive progression of AD. The remaining items, on the other hand, captured some of the preclinical changes prior to the symptom onset, but performed much better right after the symptom onset. Currently ongoing prevention trials on preclinical AD of elderly individuals may need to re-assess the sample sizes and statistical power.

[Progress of clinical correlation research on migraine and glaucoma]

Migraine is a common primary headache disorder. The estimated annual prevalence rate of migraine in China is 9.3%. Migraine is typically involved with a series of ocular symptoms including glaucoma, visual performance tests relevant to glaucoma exhibited correlation between glaucoma and migraine. Even though migraine patients exhibit no glaucoma-related signs during intermissions of migraine attacks, the results of visual function tests (visual field, electrophysiology, ocular imaging) relevant to glaucoma still indicate abnormalities. It is fairly typical that most of the patients may neglect their ocular problems when migraine breaks out. Epidemiological data suggests an increasing prevalence of migraine patients with glaucoma, particularly normal tension glaucoma. This paper reviews and discusses the effect of migraine on the clinical assessment and diagnosis of glaucoma. (Chin J Ophthalmol, 2018, 54: 224-228).

NEDL2 regulates enteric nervous system and kidney development in its Nedd8 ligase activity-dependent manner

The GDNF (Glial cell line-derived neurotrophic factor)/Ret/Akt signaling pathway is essential to the development of ENS (enteric nervous system) as well as kidney. We previously showed that the HECT-type E3 ligase NEDL2 (Nedd4-like ligase 2) is required for the ENS development by activating GDNF/Ret/Akt. However, the underlying mechanism remains unknown. Here we show that in addition to ENS, NEDL2 is also pivotal for kidney development since about 1/3 of Nedl2-deficient mice displayed postnatal unilateral or bilateral kidney hydronephrosis. Double knockout of Nedl1 and Nedl2 in mice leads to postnatal lethal within 2 weeks and the phenotypes resemble those of Nedl2 single knockout mice. Surprisingly, its close member NEDL1 is dispensable for ENS and kidney function and the reason is lack of NEDL1 expression in these systems during early development. Furthermore, biochemical analysis indicated that NEDL2 appears to act like a scaffold protein to recruit SHC, Grb2, PI3K (p110 and p85), PDK1 and Akt together to promote the signaling transduction. Intriguingly, we found that NEDL2 harbours intrinsic Nedd8 ligase activity with cysteine 1341 as the core site. NEDL2 upregulates GDNF-stimulated Akt activity dependent of its Nedd8 ligase activity but not its ubiquitin ligase activity. These findings demonstrate that NEDL2 but not NEDL1 is required for ENS and kidney development in a unique Nedd8 ligase-dependent manner.

Indistinguishable heralded single photon generation via relative temporal multiplexing of two sources

Generating N single photons simultaneously is a formidable challenge due to the lack of deterministic single photon sources. Recent work [New J. Phys. 19, 063013 (2017] has proposed a relative multiplexing scheme that can enhance the N single photons probability with a minimum of active switching resources. We experimentally demonstrate relative temporal multiplexing on two photon sources with a 90% additional enhancement over the standard temporal multiplexing scheme demonstrated previously. 88 ± 11% visibility of Hong-Ou-Mandel quantum interference verifies the indistinguishability of the heralded single photons after the synchronization. This proof-of-principle demonstration points out the potential significance of the relative multiplexing scheme for large-scale photonic quantum information processing.

Modulator figure of merit for short reach data links

The traditional Mach-Zehnder modulator (MZM) figure of merit (FOM) has been defined as (V_π²)/υ_3dBe, and works effectively for LiNbO₃ long haul modulators. However, for plasma dispersion based electro-optic modulators, or any modulator that has an inherent relationship between its bandwidth, required drive voltage, and optical insertion loss/gain, this FOM is inappropriate. This is particularly true for short reach links with no optical amplification. In the following, we propose a new modulator FOM (M-FOM) based on device metrics that are essential for short-reach links, such as the peak-to-peak drive voltage, modulator rise-fall time, and relative optical modulation amplitude. Link sensitivity measurements from two MZMs that have different bandwidths and optical losses are compared using our M-FOM to demonstrate its utility. Furthermore, we present a novel application protocol of our M-FOM to provide deeper insight into the relative system impact that modulator performance has on data links with no optical amplification, by taking the ratio of M-FOMs from two modulators driven with the same radio frequency drive power.

The Kinase Activity-deficient Isoform of the Protein Araf Antagonizes Ras/Mitogen-activated Protein Kinase (Ras/MAPK) Signaling in the Zebrafish Embryo

Raf kinases are important components of the Ras-Raf-Mek-Erk pathway and also cross-talk with other signaling pathways. Araf kinase has been demonstrated to inhibit TGF-β/Smad2 signaling by directly phosphorylating and accelerating degradation of activated Smad2. In this study, we show that the araf gene expresses in zebrafish embryos to produce a shorter transcript variant, araf-tv2, in addition to the full-length variant araf-tv1. araf-tv2 is predicted to encode a C-terminally truncated peptide without the kinase activity domain. Araf-tv2 can physically associate with Araf-tv1 but does not antagonize the inhibitory effect of Araf-tv1 on TGF-β/Smad2 signaling. Instead, Araf-tv2 interacts strongly with Kras and Nras, ultimately blocking MAPK activation by these Ras proteins. In zebrafish embryos, overexpression of araf-tv2 is sufficient to inhibit Fgf/Ras-promoted Erk activation, mesodermal induction, dorsal development, and neuroectodermal posteriorization. Therefore, different isoforms of Araf may participate in similar developmental processes but by regulating different signaling pathways.

Distributed electrode Mach-Zehnder modulator with double-pass phase shifters and integrated inductors

A novel high-speed Mach-Zehnder modulator (MZM) fully integrated into a 90 nm CMOS process is presented. The MZM features 'double-pass' optical phase shifter segments, and the first use of integrated inductors in a 'velocity-matched' distributed-electrode configuration.

Enhancing the heralded single-photon rate from a silicon nanowire by time and wavelength division multiplexing pump pulses

Heralded single photons produced on a silicon chip represent an integrated photon source solution for scalable photonic quantum technologies. The key limitation of such sources is their non-deterministic nature introduced by the stochastic spontaneous four-wave mixing (SFWM) process. Active spatial and temporal multiplexing can improve this by enhancing the single-photon rate without degrading the quantum signal-to-noise ratio. Here, taking advantage of the broad bandwidth of SFWM in a silicon nanowire, we experimentally demonstrate heralded single-photon generation from a silicon nanowire pumped by time and wavelength division multiplexed pulses. We show a 90±5% enhancement on the heralded photon rate at the cost of only 14±2% reduction to the signal-to-noise ratio, close to the performance found using only time division multiplexed pulses. As single-photon events are distributed to multiple wavelength channels, this new scheme overcomes the saturation limit of avalanche single-photon detectors and will improve the ultimate performance of such photon sources.

The Statistical Modeling of Aging and Risk of Transition Project: Data Collection and Harmonization Across 11 Longitudinal Cohort Studies of Aging, Cognition, and Dementia

Longitudinal cognitive trajectories and other factors associated with mixed neuropathologies (such as Alzheimer's disease with co-occurring cerebrovascular disease) remain incompletely understood, despite being the rule and not the exception in older populations. The Statistical Modeling of Aging and Risk of Transition study (SMART) is a consortium of 11 different high-quality longitudinal studies of aging and cognition (N=11,541 participants) established for the purpose of characterizing risk and protective factors associated with subtypes of age-associated mixed neuropathologies (N=3,001 autopsies). While brain donation was not required for participation in all SMART cohorts, most achieved substantial autopsy rates (i.e., > 50%). Moreover, the studies comprising SMART have large numbers of participants who were followed from intact cognition and transitioned to cognitive impairment and dementia, as well as participants who remained cognitively intact until death. These data provide an exciting opportunity to apply sophisticated statistical methods, like Markov processes, that require large, well-characterized samples. Thus, SMART will serve as an important resource for the field of mixed dementia epidemiology and neuropathology.

Destabilizing LSD1 by Jade-2 promotes neurogenesis: an antibraking system in neural development

Histone H3K4 demethylase LSD1 plays an important role in stem cell biology, especially in the maintenance of the silencing of differentiation genes. However, how the function of LSD1 is regulated and the differentiation genes are derepressed are not understood. Here, we report that elimination of LSD1 promotes embryonic stem cell (ESC) differentiation toward neural lineage. We showed that the destabilization of LSD1 occurs posttranscriptionally via the ubiquitin-proteasome pathway by an E3 ubiquitin ligase, Jade-2. We demonstrated that Jade-2 is a major LSD1 negative regulator during neurogenesis in vitro and in vivo in both mouse developing cerebral cortices and zebra fish embryos. Apparently, Jade-2-mediated degradation of LSD1 acts as an antibraking system and serves as a quick adaptive mechanism for re-establishing epigenetic landscape without more laborious transcriptional regulations. As a potential anticancer strategy, Jade-2-mediated LSD1 degradation could potentially be used in neuroblastoma cells to induce differentiation toward postmitotic neurons.

Meta-analysis of the association of oestrogen receptor-beta gene RsaI (G/A) and AluI (A/G) polymorphisms with male infertility

A more precise assessment of association of oestrogen receptor-beta genes RsaI(G/A) and AluI(A/G) polymorphisms with male infertility from current contradictory results is the aim of this meta-analysis including five RsaI and six AluI studies respectively. No association was observed between infertility and RsaI or AluI. In the stratified analysis by ethnicity, increased risk was found among Caucasians with GA versus GG (OR = 2.263, 95% CI = 1.073-4.776, I(2)  = 57.1%) and dominant model (OR = 2.117, 95% CI = 1.018-4.403, I(2)  = 49.0%) of RsaI. It was not observed for AluI. In the stratified analysis by infertility subtypes, a reduced risk in GA of AluI was observed among azoospermia or severe oligospermia (GA versus AA: OR = 0.686, 95% CI = 0.498-0.945, I(2)  = 21.2%; recessive model: OR = 1.403, 95% CI = 1.056-1.864, I(2)  = 31.7%), and reduced risk was in recessive model (OR = 0.650, 95% CI = 0.446-0.948, I(2)  = 0.0%) of subtypes, except for azoospermia or severe oligospermia. However, this finding was not observed in RsaI. The meta-analysis showed GA and GG of AluI are possibly resistant factors for spermatogenesis dysfunction and deteriorated sperm quality.

Bidirectional multiplexing of heralded single photons from a silicon chip

We demonstrate integrated spatial multiplexing of heralded single photons generated from a single 96 μm long silicon photonic crystal waveguide in a bidirectional pump configuration. By using a low-loss fiber-coupled opto-ceramic switch, the multiplexing technique enhances the brightness of the single photon source by 51.2±4.0% while maintaining the coincidence-to-accidental ratio. Compared with the demonstration of multiplexing two individual sources, the bidirectional pump scheme represents a twofold reduction in the footprint of nonlinear devices for future large-scale integration of on-chip single photon sources. The 51.2±4.0% gain will make any quantum operation requiring n photons 1.5(n) times faster.

Preclinical trials in autosomal dominant AD: implementation of the DIAN-TU trial

The Dominantly Inherited Alzheimer's Network Trials Unit (DIAN-TU) was formed to direct the design and management of interventional therapeutic trials of international DIAN and autosomal dominant Alzheimer's disease (ADAD) participants. The goal of the DIAN-TU is to implement safe trials that have the highest likelihood of success while advancing scientific understanding of these diseases and clinical effects of proposed therapies. The DIAN-TU has launched a trial design that leverages the existing infrastructure of the ongoing DIAN observational study, takes advantage of a variety of drug targets, incorporates the latest results of biomarker and cognitive data collected during the observational study, and implements biomarkers measuring Alzheimer's disease (AD) biological processes to improve the efficiency of trial design. The DIAN-TU trial design is unique due to the sophisticated design of multiple drugs, multiple pharmaceutical partners, academics servings as sponsor, geographic distribution of a rare population and intensive safety and biomarker assessments. The implementation of the operational aspects such as home health research delivery, safety magnetic resonance imagings (MRIs) at remote locations, monitoring clinical and cognitive measures, and regulatory management involving multiple pharmaceutical sponsors of the complex DIAN-TU trial are described.

Integrated spatial multiplexing of heralded single-photon sources

The non-deterministic nature of photon sources is a key limitation for single-photon quantum processors. Spatial multiplexing overcomes this by enhancing the heralded single-photon yield without enhancing the output noise. Here the intrinsic statistical limit of an individual source is surpassed by spatially multiplexing two monolithic silicon-based correlated photon pair sources in the telecommunications band, demonstrating a 62.4% increase in the heralded single-photon output without an increase in unwanted multipair generation. We further demonstrate the scalability of this scheme by multiplexing photons generated in two waveguides pumped via an integrated coupler with a 63.1% increase in the heralded photon rate. This demonstration paves the way for a scalable architecture for multiplexing many photon sources in a compact integrated platform and achieving efficient two-photon interference, required at the core of optical quantum computing and quantum communication protocols.

The effect of mahogunin gene mutant on reproduction in male mice: a new sight for infertility?

Mahogunin is an important mediator of chromogenesis and neurodegeneration. Mahoganoid is a mutation of the mahogunin gene, which causes a pleiotropic phenotype that includes suppression of obesity, spongiform neurodegeneration and improvement of insulin sensitivity. Our previous research found that mahoganoid widely expressed in the male rat reproductive system, and mahoganoid-deficient mice have reduced embryonic viability. But the reproductive change in mahogunin knockout (md(nc) ) male mice has not been reported previously. Here, we report that the mahogunin mRNA also widely exists in reproductive system of male mice, and its mRNA expression in the testis was in accordance with the first spermatogenesis wave cycle. Moreover, we find that md(nc) male mice were able to mate with females but no pups are delivered. Besides, the sperms' active progressive motility and hormone secretion (E2, FSH, LH, PRL) were obviously decreased while abnormal sperm rate showed no significant difference in md(nc) compared to wild-type (WT) male mice. This study indicates the mahogunin deficiency results in the infertility of male mice, disruption of hormones secretion and impaired active progressive motility, which may additionally illuminate the aetiology of male infertility in human.