Multi-stimulus perception and visualization by an intelligent liquid metal-elastomer architecture

Multi-stimulus responsive soft materials with integrated functionalities are elementary blocks for building soft intelligent systems, but their rational design remains challenging. Here, we demonstrate an intelligent soft architecture sensitized by magnetized liquid metal droplets that are dispersed in a highly stretchable elastomer network. The supercooled liquid metal droplets serve as microscopic latent heat reservoirs, and their controllable solidification releases localized thermal energy/information flows for enabling programmable visualization and display. This allows the perception of a variety of information-encoded contact (mechanical pressing, stretching, and torsion) and noncontact (magnetic field) stimuli as well as the visualization of dynamic phase transition and stress evolution processes, via thermal and/or thermochromic imaging. The liquid metal-elastomer architecture offers a generic platform for designing soft intelligent sensing, display, and information encryption systems.

Enhancing gestational diabetes mellitus risk assessment and treatment through GDMPredictor: a machine learning approach

BACKGROUND

Gestational diabetes mellitus (GDM) is a serious health concern that affects pregnant women worldwide and can lead to adverse pregnancy outcomes. Early detection of high-risk individuals and the implementation of appropriate treatment can enhance these outcomes.

METHODS

We conducted a study on a cohort of 3467 pregnant women during their pregnancy, with a total of 5649 clinical and biochemical records collected. We utilized this dataset as our training dataset to develop a web server called GDMPredictor. The GDMPredictor utilizes advanced machine learning techniques to predict the risk of GDM in pregnant women. We also personalize treatment recommendations based on essential biochemical indicators, such as A1MG, BMG, CysC, CO2, TBA, FPG, and CREA. Our assessment of GDMPredictor's effectiveness involved training it on the dataset of 3467 pregnant women and measuring its ability to predict GDM risk using an AUC and auPRC.

RESULTS

GDMPredictor demonstrated an impressive level of precision by achieving an AUC score of 0.967. To tailor our treatment recommendations, we use the GDM risk level to identify higher risk candidates who require more intensive care. The GDMPredictor can accept biochemical indicators for predicting the risk of GDM at any period from 1 to 24 weeks, providing healthcare professionals with an intuitive interface to identify high-risk patients and give optimal treatment recommendations.

CONCLUSIONS

The GDMPredictor presents a valuable asset for clinical practice, with the potential to change the management of GDM in pregnant women. Its high accuracy and efficiency make it a reliable tool for doctors to improve patient outcomes. Early identification of high-risk individuals and tailored treatment can improve maternal and fetal health outcomes http://www.bioinfogenetics.info/GDM/ .

Twisted moiré photonic crystal enabled optical vortex generation through bound states in the continuum

The twisted stacking of two layered crystals has led to the emerging moiré physics as well as intriguing chiral phenomena such as chiral phonon and photon generation. In this work, we identified and theoretically formulated a non-trivial twist-enabled coupling mechanism in twisted bilayer photonic crystal (TBPC), which connects the bound state in the continuum (BIC) mode to the free space through the twist-enabled channel. Moreover, the radiation from TBPC hosts an optical vortex in the far field with both odd and even topological orders. We quantitatively analyzed the twist-enabled coupling between the BIC mode and other non-local modes in the photonic crystals, giving rise to radiation carrying orbital angular momentum. The optical vortex generation is robust against geometric disturbance, making TBPC a promising platform for well-defined vortex generation. As a result, TBPCs not only provide a new approach to manipulating the angular momentum of photons, but may also enable novel applications in integrated optical information processing and optical tweezers. Our work broadens the field of moiré photonics and paves the way toward the novel application of moiré physics.

Single-pixel reconstructive mid-infrared micro-spectrometer

Miniaturized spectrometers in the mid-infrared (MIR) are critical in developing next-generation portable electronics for advanced sensing and analysis. The bulky gratings or detector/filter arrays in conventional micro-spectrometers set a physical limitation to their miniaturization. In this work, we demonstrate a single-pixel MIR micro-spectrometer that reconstructs the sample transmission spectrum by a spectrally dispersed light source instead of spatially grated light beams. The spectrally tunable MIR light source is realized based on the thermal emissivity engineered via the metal-insulator phase transition of vanadium dioxide (VO₂). We validate the performance by showing that the transmission spectrum of a magnesium fluoride (MgF₂) sample can be computationally reconstructed from sensor responses at varied light source temperatures. With potentially minimum footprint due to the array-free design, our work opens the possibility where compact MIR spectrometers are integrated into portable electronic systems for versatile applications.

[CD5L is elevated in the serum of patients with candidemia and promotes disease progression in mouse models]

OBJECTIVE

To investigate the changes of CD5L levels in patients with candidemia and explore the role of CD5L in progression of candidemia.

METHODS

Twenty healthy control individuals, 27 patients with bacteremia and 35 patients with candidemia were examined for serum CD5L levels using ELISA, and the correlations of CD5L level with other serological indicators were analyzed. A C57BL/6 mouse model of candidemia induced by intravenous injection of Candida albicans were treated with intraperitoneal injection of recombinant CD5L protein, and renal histopathological and serological changes were analyzed to assess renal injures. The effects of CD5L treatment on general condition, fungal burden, of survival of the mice were observed, and the changes in serum IL-6 and IL-8 levels of the mice were detected using ELISA.

RESULTS

CD5L levels were significantly elevated in patients with candidemia and positively correlated with WBC, BDG, Scr and PCT levels. The mouse model of candidemia also showed significantly increased serum and renal CD5L levels, and CD5L treatment significantly increased fungal burden in the renal tissue, elevated IL-6 and IL-8 levels in the serum and kidney, aggravated renal tissue damage, and reduced survival rate of candidemia mice.

CONCLUSION

Serum CD5L levels are increased in patients with candidemia, and treatment with CD5L aggravates candidemia in mouse models.

A167 HISTOLOGICAL REMISSION PLACEBO RATES IN ULCERATIVE COLITIS TRIALS: A SYSTEMATIC REVIEW AND META-ANALYSIS

Background

High histologic remission rates have been reported with placebos in randomized controlled trials (RCTs) evaluating ulcerative colitis (UC) therapies and have varied based on trial designs. We performed a systematic review and meta-analysis to quantify placebo histological remission rates and identify factors influencing those rates.

Purpose

This systematic review aims to improve future trials design and minimize placebo rates in UC trials.

Method

MEDLINE, EMBASE, and the Cochrane library were searched from inception of the databases until December 2021. We included placebo-controlled RCTs of adult patients with UC treated with aminosalicylates, corticosteroids, immunosuppressives, biologics, and small molecules. We pooled estimates using a random-effects model and performed subgroup analysis as well as meta-regression to evaluate the effect of different covariates on placebo rates.

Result(s)

Thirty-three studies (30 induction and 3 maintenance) were included. The overall placebo histological remission rate was 15.7% [95% CI 12.9-19%] across all 33 studies (Figure). High heterogeneity was observed among studies with I² = 62.10%. In induction studies, the pooled estimate of histological remission was 15.8% [95% CI 12.7-19.5%], while in maintenance studies the pooled estimate was 14.5% [95% CI 8.4-24%]. Subgroup analysis revealed statistically significant differences in placebo rates when accounting for background medications, the intervention drug class, and disease severity [p= 0.041, 0.025, and 0.025, respectively]. There was no statistical difference between induction vs. maintenance studies or between different histological scales [p= 0.771, and 0.075, respectively]. Meta-regression showed similar results except that the therapy used was not statistically significant [p-value= 0.059].

Image

Conclusion(s)

Placebo histological remission rates range from 13-19% in UC RCTs, but studies are highly heterogeneous. Factors found to influence placebo rates include presence of background medications, the drug used and the disease severity in UC patients. These observations have important implications in informing future trial designs to minimize placebo rates and reduce heterogeneity.

Disclosure of Interest

M. Youssef: None Declared, K. Dong: None Declared, S. J. Lee: None Declared, N. Narula Speakers bureau of: received honoraria from Janssen, Abbvie, Takeda, Pfizer, Merck, Sandoz, Novartis, and Ferring

Transcription factor MdLSD1 negatively regulates α-farnesene biosynthesis in apple-fruit skin tissue

α-Farnesene is a sesquiterpene present in plants. It was first discovered in apples. It plays an important role in the plant defence response and is considered a key factor in the occurrence of superficial scald. The gene encoding α-farnesene synthase, which is the last key enzyme in the biosynthetic pathway of α-farnesene in apple fruit, has become the primary target enzyme for controlling the genetic manipulation of α-farnesene biosynthesis. In this study, the yeast one-hybrid assay and the dual luciferase assay were used to ascertain the relationship between MdLSD1 and MdAFS. Real-time PCR was used to analyse the molecular mechanism underlying the regulation of MdAFS by MdLSD1. Our results revealed that transcription factor MdLSD1, which is closely related to programmed cell death in apple fruit tissues, binds to MdAFS. Transient transformation of apple skin with vectors overexpressing MdLSD1 showed that the gene negatively regulates MdAFS. Overall, we suggest that MdLSD1 negatively regulates MdAFS. Our results are of great significance for future research on the transcriptional regulation of the α-farnesene synthase gene and provide a new direction for exploring the specific mechanism of programmed cell death involved in superficial-scald incidence.

Room-temperature skyrmion lattice in a layered magnet (Fe0.5Co0.5)5GeTe2

Novel magnetic ground states have been stabilized in two-dimensional (2D) magnets such as skyrmions, with the potential next-generation information technology. Here, we report the experimental observation of a Néel-type skyrmion lattice at room temperature in a single-phase, layered 2D magnet, specifically a 50% Co-doped Fe₅GeTe₂ (FCGT) system. The thickness-dependent magnetic domain size follows Kittel's law. The static spin textures and spin dynamics in FCGT nanoflakes were studied by Lorentz electron microscopy, variable-temperature magnetic force microscopy, micromagnetic simulations, and magnetotransport measurements. Current-induced skyrmion lattice motion was observed at room temperature, with a threshold current density, j_th = 1 × 10⁶ A/cm². This discovery of a skyrmion lattice at room temperature in a noncentrosymmetric material opens the way for layered device applications and provides an ideal platform for studies of topological and quantum effects in 2D.

Temperature-adaptive radiative coating for all-season household thermal regulation

[Figure: see text].

Conjugating MMAE to a novel anti-HER2 antibody for selective targeted delivery

OBJECTIVE

To investigate the target delivery properties of RC48-ADC, a novel antibody drug conjugate (ADC) comprising cytotoxic monomethyl auristatin E (MMAE) and an anti-human epidermal growth factor receptor 2 (HER2) antibody tethered via valine-citrulline linker, in vitro and in vivo.

MATERIALS AND METHODS

Dissociation rate of MMAE from RC48-ADC was used as an estimate of its stability in serum. Cytotoxicity of the antibody and RC48-ADC towards multiple cell lines was measured. Subcellular distribution of the drug was determined by fluorescence imaging. The mechanism of lysosome targeting was verified. Endocytic pathways of RC48-ADC were assessed by the cellular fluorescence intensity of fluorescently-labelled drugs. Intracellular and extracellular distribution of MMAE was analysed after RC48-ADC or MMAE administration to characterize MMAE release. The serum and tumour concentration of MMAE was compared after tail-vein injection of RC48-ADC into tumour-bearing mice.

RESULTS

RC48-ADC was highly stable in human serum. HER2-overexpressed cell line SK-BR-3 proliferation was stronger when suppressed by RC48-ADC than by the naked antibody. Both RC48-ADC and naked antibody were internalized via caveolae-mediated and clathrin-mediated endocytosis and concentrated in lysosomes. Higher HER2 expression was associated with enhanced uptake and intracellular release of conjugated MMAE; free MMAE could kill tumour cells via the bystander effect. Although serum RC48-ADC concentration was higher than that in tumours, exposure of MMAE in tumours was ~200 times higher than in serum, which rationalized the reduced toxicity of RC48-ADC.

CONCLUSIONS

In vitro and in vivo experiments confirmed the targeted transport and release of RC48-ADC; it could selectively deliver MMAE to the targeted HER2-positive cell or tumour tissue, which could reduce off-target toxicity and enhance anti-tumour potency in humans.

Flat Bands in Magic-Angle Bilayer Photonic Crystals at Small Twists

The new physics of magic-angle twisted bilayer graphene (TBG) motivated extensive studies of flat bands hosted by moiré superlattices in van der Waals structures, inspiring the investigations into their photonic counterparts with potential applications including Bose-Einstein condensation. However, correlation between photonic flat bands and bilayer photonic moiré systems remains unexplored, impeding further development of moiré photonics. In this work, we formulate a coupled-mode theory for low-angle twisted bilayer honeycomb photonic crystals as a close analogy of TBG, discovering magic-angle photonic flat bands with a non-Anderson-type localization. Moreover, the interlayer separation constitutes a convenient degree of freedom in tuning photonic moiré bands without high pressure. A phase diagram is constructed to correlate the twist angle and separation dependencies to the photonic magic angles. Our findings reveal a salient correspondence between fermionic and bosonic moiré systems and pave the avenue toward novel applications through advanced photonic band or state engineering.

Analysis of the relationship between microRNA-31 and interferon regulatory factor-1 in hepatocellular carcinoma cells

OBJECTIVE

MicroRNAs (miRNAs) play a role in the pathogenesis of hepatocellular carcinoma (HCC). This study was designed to elucidate the role of microRNA-31 (miR-31) in HCC.

MATERIALS AND METHODS

HuH7 cell lines were transfected with miR-31 mimic or miR-31 inhibitor to investigate the role of miR-31 in regulating interferon regulatory factor-1 (IRF-1). The mRNA and protein expression levels of IRF-1 were quantitatively detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) and Western blot, respectively. Subsequently, Dual-Luciferase reporter assay was also performed.

RESULTS

The expression level of miR-31 was significantly up-regulated in HuH7 cells when compared with that in primary human hepatocytes (hHC). Dual-Luciferase reporter assay indicated that IRF-1 was the direct target of miR-31. The expression levels of IRF-1 were decreased in HuH7 and HepG2 cell lines. IRF-1 was negatively correlated with miR-31 in HCC tissues and paired adjacent tissues. The expression level of miR-31 was inversely correlated with IRF-1. MiR-31 inhibitor up-regulated the expression levels of IRF-1 in HuH7 cells, whereas miR-31 mimic down-regulated the expression levels of IRF-1. Furthermore, the miR-31 mimic repressed IRF-1-3'UTR reporter activity, whereas the miR-31 inhibitor enhanced IRF-1-3'UTR reporter activity depending on the concentration of miR-31 mimic and miR-31 inhibitor.

CONCLUSIONS

These results indicated that miR-31 can regulate the expression level of IRF-1 in HCC, which probably provided novel theoretical evidence for the application of target miR-31 treatment of HCC.

Cinnamic Acid Increased the Incidence of Fusarium Wilt by Increasing the Pathogenicity of Fusarium oxysporum and Reducing the Physiological and Biochemical Resistance of Faba Bean, Which Was Alleviated by Intercropping With Wheat

BACKGROUND

Continuous cropping has resulted in the accumulation of self-toxic substances in faba beans which has restricted their global production. Intercropping is widely used to alleviate these problems.

AIMS

To explore the role of cinnamic acid stress in faba bean physiology and disease resistance, and the potential mitigating effects of intercropping the faba bean with wheat.

METHODS

Faba bean seedlings were grown with or without wheat in both field and hydroponic conditions in the presence of different cinnamic acid concentrations and Fusarium oxysporum (FOF), the occurrence of. Fusarium-mediated wilt and oxidative stress, as well as plant growth indices and the anti-pathogen defense system were analyzed.

RESULTS

Cinnamic acid significantly increased Fusarium pathogenicity, inhibited the activity of defense enzymes and reduced the ability of plants to resist pathogens, indicating the importance of cinnamic acid in the promotion of Fusarium wilt resulting in reduced seedling growth. Intercropping with wheat improved plant resistance by alleviating cinnamic acid-induced stress, which promoted crop growth and decreased the incidence and disease index of Fusarium wilt.

CONCLUSION

Cinnamic acid promotes Fusarium wilt by stimulating pathogen enzyme production and destroying the defense capability of faba bean roots. Intercropping reduces Fusarium wilt by alleviating the damage caused by cinnamic acid to the defense system of the faba bean root system.

Millikelvin-resolved ambient thermography

Temperature sensitivity of thermography is boosted by over 15 times to achieve millikelvin-resolution near ambient temperature.

Tunable analog thermal material

Naturally-occurring thermal materials usually possess specific thermal conductivity (κ), forming a digital set of κ values. Emerging thermal metamaterials have been deployed to realize effective thermal conductivities unattainable in natural materials. However, the effective thermal conductivities of such mixing-based thermal metamaterials are still in digital fashion, i.e., the effective conductivity remains discrete and static. Here, we report an analog thermal material whose effective conductivity can be in-situ tuned from near-zero to near-infinity κ. The proof-of-concept scheme consists of a spinning core made of uncured polydimethylsiloxane (PDMS) and fixed bilayer rings made of silicone grease and steel. Thanks to the spinning PDMS and its induced convective effects, we can mold the heat flow robustly with continuously changing and anisotropic κ. Our work enables a single functional thermal material to meet the challenging demands of flexible thermal manipulation. It also provides platforms to investigate heat transfer in systems with moving components.

A Thermal Radiation Modulation Platform by Emissivity Engineering with Graded Metal-Insulator Transition

Thermal radiation from a black body increases with the fourth power of absolute temperature (T⁴ ), an effect known as the Stefan-Boltzmann law. Typical materials radiate heat at a portion of this limit, where the portion, called integrated emissivity (ε_int ), is insensitive to temperature (|dε_int /dT| ≈ 10^-4 °C^-1 ). The resultant radiance bound by the T⁴ law limits the ability to regulate radiative heat. Here, an unusual material platform is shown in which ε_int can be engineered to decrease in an arbitrary manner near room temperature (|dε_int /dT| ≈ 8 × 10^-3 °C^-1 ), enabling unprecedented manipulation of infrared radiation. As an example, ε_int is programmed to vary with temperature as the inverse of T⁴ , precisely counteracting the T⁴ dependence; hence, thermal radiance from the surface becomes temperature-independent, allowing the fabrication of flexible and power-free infrared camouflage with unique advantage in performance stability. The structure is based on thin films of tungsten-doped vanadium dioxide where the tungsten fraction is judiciously graded across a thickness less than the skin depth of electromagnetic screening.

Blue light disrupts the circadian rhythm and create damage in skin cells

On a daily basis, the skin is exposed to many environmental stressors and insults. Over a 24-h natural cycle, during the day, the skin is focused on protection; while at night, the skin is focused on repairing damage that occurred during daytime and getting ready for the next morning. Circadian rhythm provides the precise timing mechanism for engaging those different pathways necessary to keep a healthy skin through clock genes that are present in all skin cells. The strongest clue for determining cellular functions timing is through sensing light or absence of light (darkness). Here, we asked the question if blue light could be a direct entrainment signal to skin cells and also disrupt their circadian rhythm at night. Through a reporter assay for per1 transcription, we demonstrate that blue light at 410 nm decreases per1 transcription in keratinocytes, showing that epidermal skin cells can sense light directly and control their own clock gene expression. This triggers cells to "think" it is daytime even at nighttime. Elsewhere, we measured different skin cell damage because of blue light exposure (at different doses and times of exposure) vs. cells that were kept in full darkness. We show an increase in ROS production, DNA damage and inflammatory mediators. These deleterious effects can potentially increase overall skin damage over time and ultimately accelerates ageing.

[Follow-up analysis on change of serum total cholesterol concentration in rural residents in Shanxi province]

Objective: To analyze the longitudinal change of serum total cholesterol concentration in 733 rural residents in Shanxi province. Methods: Based on the residents of five rural areas in Shanxi province who participated in China nutrition and health survey in 2002, a follow-up survey was conducted in 2015. Fasting venous blood of the participants was collected and serum TC concentration was tested by cholesterol oxidase method. Results: Of 733 participants, 332 were male and 401 were female. In 2002 baseline survey, the age of the participants was (42.6±9.5) years old, 76.2% of male and 83.8% of female had junior middle school education or below. Proportion of smoking were 65.7% and 1.2%, drinking were 26.8% and 4.0%, obesity were 6.3% and 12.0%, and central obesity were 27.1% and 31.9%, respectively in male and female. The follow-up age of participants in 2015 was (55.8±9.5) years old, proportion of smoking changed to 48.2% and 1.5%, drinking were 49.7% and 3.0%, obesity increased to 11.8% and 18.2% and central obesity increased to 41.6% and 53.6%, respectively in male and female. The overall serum TC level increased from (3.82±0.89) mmol/L to (4.72±0.97) mmol/L with an average increase of 27.2%, which increased from (3.84±0.94) mmol/L to (4.54±0.93) mmol/L in male with an average increase of 22.7%, and increased from (3.81±0.84) mmol/L to (4.86±0.98) mmol/L in female with an average increase of 30.9%. The serum TC levels in 18-, 30-, 40-, and 50-59 years old group increased from (3.42±0.83), (3.72±0.77), (3.90±0.83) and (4.00±1.03) mmol/L to (4.38±1.01), (4.79±0.92), (4.73±0.99) and (4.76±0.96) mmol/L, with average increase range of 31.4%, 32.1%, 25.2% and 22.6%, respectively. The mean serum TC levels between two years all had statistically significant difference among groups of gender, age, education, marital status, family history of cardiovascular disease, smoking, drinking, BMI and waist circumference after paired t-test and ANOVA analysis (P<0.01). Conclusion: The longitudinal serum TC level of rural residents in Shanxi province increased rapidly.

Adenosine inhibits migration, invasion and induces apoptosis of human cervical cancer cells

Extracellular adenosine is a key signaling molecule which mediates immune suppression, angiogenesis, and regulates cancer cells growth. The effect of adenosine on cervical cancer cells migration and invasion has not been well studied. In the current study, we used Hela and SiHa cell lines to evaluate the effects of adenosine on cervical cancer cells migration, invasion, and apoptosis. The results showed that adenosine treatment inhibited the migration and invasion activities of Hela and SiHa cells. Moreover, by determining the expression of molecules which were involved in epithelial to mesenchymal transition (EMT) progress, we found that epithelial marker E-cadherin was significantly increased in response to adenosine treatment, while the mesenchymal markers including N-cadherin and fibronectin were decreased. These data suggested that adenosine inhibited cervical cancer cells via repressing the EMT progress. The flow cytometry analysis showed that adenosine could also induce cervical cancer cell apoptosis, which mechanism was further confirmed by investigating the expression levels of apoptosis related molecules, via activating mitochondrial apoptosis pathway. These data might suggest that adenosine could be used as an agent for the treatment of cervical cancer.

All-Silicon Broadband Ultraviolet Metasurfaces

Featuring high photon energy and short wavelength, ultraviolet (UV) light enables numerous applications such as high-resolution imaging, photolithography, and sensing. In order to manipulate UV light, bulky optics are usually required, and hence do not meet the fast-growing requirements of integration in compact systems. Recently, metasurfaces have shown unprecedented control of light, enabling substantial miniaturization of photonic devices from terahertz to visible regions. However, material challenges have hampered the realization of such functionalities at shorter wavelengths. Herein, it is experimentally demonstrated that all-silicon (Si) metasurfaces with thicknesses of only one-tenth of the working wavelength can be designed and fabricated to manipulate broadband UV light with efficiencies comparable to plasmonic metasurface performance in infrared (IR). Also, for the first time, photolithography enabled by metasurface-generated UV holograms is shown. Such performance enhancement is attributed to increased scattering cross sections of Si antennas in the UV range, which is adequately modeled via a circuit. The new platform introduced here will deepen the understanding of light-matter interactions and introduce even more material options to broadband metaphotonic applications, including those in integrated photonics and holographic lithography technologies.

Subwavelength light confinement and enhancement enabled by dissipative dielectric nanostructures

Dissipative loss in optical materials is considered one of the major challenges in nano-optics. Here we show that, counter-intuitively, a large imaginary part of material permittivity contributes positively to subwavelength light enhancement and confinement. The Purcell factor and the fluorescence enhancement of dissipative dielectric bowtie nanoantennas, such as Si in ultraviolet (UV), are demonstrated to be orders of magnitude higher than their lossless dielectric counterparts, which is particularly favorable in deep UV applications where metals are plasmonically inactive. The loss-facilitated field enhancement is the result of a large material property contrast and an electric field discontinuity. These dissipative dielectric nanostructures can be easily achieved with a great variety of dielectrics at their Lorentz oscillation frequencies, thus having the potential to build a completely new material platform boosting light-matter interaction over broader frequency ranges, with advantages such as bio-compatibility, CMOS compatibility, and harsh environment endurance.

A 0.2 V Micro-Electromechanical Switch Enabled by a Phase Transition

Micro-electromechanical (MEM) switches, with advantages such as quasi-zero leakage current, emerge as attractive candidates for overcoming the physical limits of complementary metal-oxide semiconductor (CMOS) devices. To practically integrate MEM switches into CMOS circuits, two major challenges must be addressed: sub 1 V operating voltage to match the voltage levels in current circuit systems and being able to deliver at least millions of operating cycles. However, existing sub 1 V mechanical switches are mostly subject to significant body bias and/or limited lifetimes, thus failing to meet both limitations simultaneously. Here 0.2 V MEM switching devices with ≳10⁶ safe operating cycles in ambient air are reported, which achieve the lowest operating voltage in mechanical switches without body bias reported to date. The ultralow operating voltage is mainly enabled by the abrupt phase transition of nanolayered vanadium dioxide (VO₂ ) slightly above room temperature. The phase-transition MEM switches open possibilities for sub 1 V hybrid integrated devices/circuits/systems, as well as ultralow power consumption sensors for Internet of Things applications.

Multifunctional Microelectro-Opto-mechanical Platform Based on Phase-Transition Materials

Along with the rapid development of hybrid electronic-photonic systems, multifunctional devices with dynamic responses have been widely investigated for improving many optoelectronic applications. For years, microelectro-opto-mechanical systems (MEOMS), one of the major approaches to realizing multifunctionality, have demonstrated profound reconfigurability and great reliability. However, modern MEOMS still suffer from limitations in modulation depth, actuation voltage, or miniaturization. Here, we demonstrate a new MEOMS multifunctional platform with greater than 50% optical modulation depth over a broad wavelength range. This platform is realized by a specially designed cantilever array, with each cantilever consisting of vanadium dioxide, chromium, and gold nanolayers. The abrupt structural phase transition of the embedded vanadium dioxide enables the reconfigurability of the platform. Diverse stimuli, such as temperature variation or electric current, can be utilized to control the platform, promising CMOS-compatible operating voltage. Multiple functionalities, including an active enhanced absorber and a reprogrammable electro-optic logic gate, are experimentally demonstrated to address the versatile applications of the MEOMS platform in fields such as communication, energy harvesting, and optical computing.

A Lithography-Free and Field-Programmable Photonic Metacanvas

The unique correspondence between mathematical operators and photonic elements in wave optics enables quantitative analysis of light manipulation with individual optical devices. Phase-transition materials are able to provide real-time reconfigurability of these devices, which would create new optical functionalities via (re)compilation of photonic operators, as those achieved in other fields such as field-programmable gate arrays (FPGA). Here, by exploiting the hysteretic phase transition of vanadium dioxide, an all-solid, rewritable metacanvas on which nearly arbitrary photonic devices can be rapidly and repeatedly written and erased is presented. The writing is performed with a low-power laser and the entire process stays below 90 °C. Using the metacanvas, dynamic manipulation of optical waves is demonstrated for light propagation, polarization, and reconstruction. The metacanvas supports physical (re)compilation of photonic operators akin to that of FPGA, opening up possibilities where photonic elements can be field programmed to deliver complex, system-level functionalities.

Enhancing Modulation of Thermal Conduction in Vanadium Dioxide Thin Film by Nanostructured Nanogaps

Efficient thermal management at the nanoscale is important for reducing energy consumption and dissipation in electronic devices, lab-on-a-chip platforms and energy harvest/conversion systems. For many of these applications, it is much desired to have a solid-state structure that reversibly switches thermal conduction with high ON/OFF ratios and at high speed. Here we describe design and implementation of a novel, all-solid-state thermal switching device by nanostructured phase transformation, i.e., modulation of contact pressure and area between two poly-silicon surfaces activated by microstructural change of a vanadium dioxide (VO₂) thin film. Our solid-state devices demonstrate large and reversible alteration of cross-plane thermal conductance as a function of temperature, achieving a conductance ratio of at least 2.5. Our new approach using nanostructured phase transformation provides new opportunities for applications that require advanced temperature and heat regulations.

Identification and characterization of the distinct expression profiles of candidate chemosensory membrane proteins in the antennal transcriptome of Adelphocoris lineolatus (Goeze)

Chemosensory membrane proteins, including odorant receptors (ORs), ionotropic receptors (IRs), gustatory receptors (GRs) and sensory neurone membrane proteins (SNMPs), are supposed to be crucial macromolecules in the insect olfactory signal transduction pathway. The alfalfa plant bug Adelphocoris lineolatus (Goeze) (Hemiptera: Miridae) is highly attracted to high-nitrogen or flowering plants and destroys many important agricultural crops. We assembled the antennal transcriptome of A. lineolatus using Illumina sequencing technology and identified a total of 108 transcripts encoding chemosensory membrane proteins (88 ORs, 12 IRs, four GRs and four SNMPs), amongst which 90 candidates appeared to be full length. Subsequently, both semiquantitative reverse transcription PCR and quantitative real-time PCR experiments were performed to investigate their tissue- and sex-biased expression profiles. The results showed that nearly all of the 108 candidate chemosensory membrane protein genes were largely expressed in adult antennae, and some genes additionally displayed significant differences in the expression levels between sexes. The results of our phylogenetic analysis and the detailed tissue- and sex-biased expression characteristics given here provide an important foundation for further understanding of the complex chemoreception system of the alfalfa plant bug and other Hemiptera species, which also could help us use chemosensory membrane proteins as targets to manipulate insect olfactory behaviour and broaden the applications of available tools for insect pest control.

Effect of SIRT6 knockdown on NF-κB induction and on residual DNA damage in cultured human skin fibroblasts

SIRT6 is a member of the sirtuin family, which is involved in multiple cellular pathways related to aging, inflammation, epigenetics, and a variety of other cellular functions, including DNA repair (1). Multiple pathways involving different cellular functions are impacted by the deacetylase activity of SIRT6. Genomic integrity is maintained by the capacity of SIRT6 to modulate the accessibility of DNA repair proteins. Glucose metabolism is suppressed by SIRT6 via the deacetylation of histones located at the promoter regions of multiple glycolytic genes and the corepression of hypoxia-inducible factor-1α. SIRT6 is also a corepressor of nuclear factor (NF)-κB, silencing NF-κB target genes through the deacetylation of histones at their promoters’ regions. We used SIRT6 small-interfering RNA as a tool to modulate residual DNA damage and NF-κB expression in human dermal fibroblasts. We measured NF-κB levels in the presence or the absence of ultraviolet B (UVB). The impact of SIRT6 knockdown as shown by a decrease in SIRT6 messenger RNA levels resulted in residual DNA damage as evaluated by the comet assay. Our results show that NF-κB was increased significantly (up to 400%) due to SIRT6 silencing in the absence of UVB, illustrating the master regulatory function of SIRT6 in inflammation. We also found a significant increase in DNA damage without UV exposure as a result of SIRT6 silencing, indicating the importance of SIRT6 in DNA repair pathways in cultured human dermal fibroblasts.

Tunable Bragg filters with a phase transition material defect layer

We propose an all-solid-state tunable Bragg filter with a phase transition material as the defect layer. Bragg filters based on a vanadium dioxide defect layer sandwiched between silicon dioxide/titanium dioxide Bragg gratings are experimentally demonstrated. Temperature dependent reflection spectroscopy shows the dynamic tunability and hysteresis properties of the Bragg filter. Temperature dependent Raman spectroscopy reveals the connection between the tunability and the phase transition of the vanadium dioxide defect layer. This work paves a new avenue in tunable Bragg filter designs and promises more applications by combining phase transition materials and optical cavities.

Modulating Photoluminescence of Monolayer Molybdenum Disulfide by Metal-Insulator Phase Transition in Active Substrates

The atomic thickness and flatness allow properties of 2D semiconductors to be modulated with influence from the substrate. Reversible modulation of these properties requires an "active," reconfigurable substrate, i.e., a substrate with switchable functionalities that interacts strongly with the 2D overlayer. In this work, the photoluminescence (PL) of monolayer molybdenum disulfide (MoS2 ) is modulated by interfacing it with a phase transition material, vanadium dioxide (VO2 ). The MoS2 PL intensity is enhanced by a factor of up to three when the underlying VO2 undergoes the thermally driven phase transition from the insulating to metallic phase. A nonvolatile, reversible way to rewrite the PL pattern is also demonstrated. The enhancement effect is attributed to constructive optical interference when the VO2 turns metallic. This modulation method requires no chemical or mechanical processes, potentially finding applications in new switches and sensors.

FRAILTY, FOOD INSECURITY, AND NUTRITIONAL STATUS IN PEOPLE LIVING WITH HIV

BACKGROUND

Nutritional status and food insecurity are associated with frailty in the general U.S. population, yet little is known about this in the aging population of people living with HIV (PLWH).

OBJECTIVES

Given the potential importance of nutrition and the amenability to intervention, we examined the association between nutritional status, food insecurity, and frailty in PLWH.

DESIGN

Cross sectional study.

SETTING

Boston, Massachusetts, U.S.A.

PARTICIPANTS

50 PLWH, age ≥45 years, recruited from a cohort study examining risk factors for cardiovascular disease.

MEASUREMENTS

Frailty, duration of HIV, use of antiretroviral therapy, disease history, food insecurity, physical function, and physical activity were assessed by questionnaire. Dietary intake was assessed using 3-day food records. Blood was drawn for CD4+ cell count, hemoglobin, hematocrit, and lipid levels. Physical measurements included height, weight, and skinfold thickness.

RESULTS

The prevalence of frailty was 16% (n=8), 44% were pre-frail (n=22) and 40% were not frail (n=20). The number of reported difficulties with 20 activities of daily living was highest in frail (mean 10.4±3.9 SD), followed by pre-frail (6.5±4.6), and lowest in not frail participants (2.0±2.3). Seven (88%) of the frail PLWH lost weight with an average weight loss of 22.9 pounds; 6 (75%) reported unintentional weight loss, and all 6 of these met the frailty criteria for weight loss of 10 or more pounds. Nine (45%) of the not frail PLWH reported losing weight with an average weight loss of 6.2 pounds; 5 (23%) reported unintentional weight loss of <10 pounds. Frail PLWH were more likely to report being food insecure than not frail PLWH (63% vs. 10%, p=0.02), and tended to have lower energy intake than not frail PLWH.

CONCLUSION

Research is needed on targeted interventions to improve food security and activities of daily living in PLWH for both the prevention and improvement of frailty.

Pond sediment magnetite grains show a distinctive microbial community

Formation of magnetite in anaerobic sediments is thought to be enhanced by the activities of iron-reducing bacteria. Geobacter has been implicated as playing a major role, as in culture its cells are often associated with extracellular magnetite grains. We studied the bacterial community associated with magnetite grains in sediment of a freshwater pond in South Korea. Magnetite was isolated from the sediment using a magnet. The magnetite-depleted fraction of sediment was also taken for comparison. DNA was extracted from each set of samples, followed by PCR for 16S bacterial ribosomal RNA (rRNA) gene and HiSeq sequencing. The bacterial communities of the magnetite-enriched and magnetite-depleted fractions were significantly different. The enrichment of three abundant operational taxonomic units (OTUs) suggests that they may either be dependent upon the magnetite grain environment or may be playing a role in magnetite formation. The most abundant OTU in magnetite-enriched fractions was Geobacter, bolstering the case that this genus is important in magnetite formation in natural systems. Other major OTUs strongly associated with the magnetite-enriched fraction, rather than the magnetite-depleted fraction, include a Sulfuricella and a novel member of the Betaproteobacteria. The existence of distinct bacterial communities associated with particular mineral grain types may also be an example of niche separation and coexistence in sediments and soils, which cannot usually be detected due to difficulties in separating and concentrating minerals.

Copy number variation detection using SNP genotyping arrays in three Chinese pig breeds

We performed genome-wide CNV detection based on SNP genotyping data of 96 Chinese-native Tibetan, Dahe and Wuzhishan pigs. These pigs are particularly interesting because of their excellent adaptation to hypoxia or small body size, which facilitates the use of them as models of different human diseases in addition to valuable agricultural animals. A total of 105 CNV regions (CNVRs) were identified, encompassing 16.71 Mb of the pig genome. Seven of 10 (70%) CNVRs selected randomly were validated by quantitative real-time PCR. Comparison with previous studies revealed 25 (23.81%) novel CNVRs, indicating that CNV coverage of the pig genome is still incomplete and there exists large diversity between pig breeds. Functional analysis of genes located in these CNVRs confirmed the high representation of genes involved in sensory perception, neurological system processes and other basic metabolic processes. In addition, the majority of these CNVRs were detected to span reported pig QTL that affect various traits, which highlighted three biologically interesting genes with copy number changes (i.e., ANKRD34B, FAM110B and ABCG1). These genes may have economic importance in pig breeding and are worth being further investigated. We also obtained some CNVRs harboring genes that had human orthologs involved in human diseases such as cardiovascular disease and Alzheimer's disease. The findings of this study are a significant extension of the coverage of CNVRs in the pig genome and provide valuable resources for follow-up-associated studies of CNVs in pig complex traits as well as important implications of human diseases.