Real-time channel selection in multi-mode multiplexing optical interconnection implemented by hybrid algorithm and material system.

Multi-mode multiplexing optical interconnection (MMOI) has been widely used as a new technology that can significantly expand communication bandwidth. However, the constant-on state of each channel in the existing MMOI systems leads to serious interference for receivers when extracting and processing information, necessitating introducing real-time selective-on function for each channel in MMOI systems. To achieve this goal, combining several practical requirements, we propose a real-time selective mode switch based on phase-change materials, which can individually tune the passing/blocking of different modes in the bus waveguide. We utilize our proposed particle swarm optimization algorithm with embedded neural network surrogate models (NN-in-PSO) to design this mode switch. The proposed NN-in-PSO significantly reduces the optimization cost, enabling multi-dimensional simultaneous optimization. The resulting mode switch offers several advantages, including ultra-compactness, rapid tuning, nonvolatility, and large extinction ratio. Then, we demonstrate the real-time channel selection function by integrating the mode switch into the MMOI system. Finally, we prove the fabricating robustness of the proposed mode switch, which paves the way for its large-scale application.

PtCu Alloy-Modified Triptycene-Based Polymer with Charge Separation for Photocatalytic Hydrogen Evolution from Water/Seawater.

Direct photocatalytic hydrogen from earth-abundant seawater is a great potential way to achieve sustainable and clean energy, yet unsatisfactory decomposition and rapid electron-hole pair recombination of catalysts hinder the solar-driven H2 conversion efficiency. Herein, we designed a series of PtCu alloy nanoparticle-modified porous triptycene-based polymers (PtxCu1-TCP) to construct the heterostructure for highly efficient hydrogen generation from photocatalytic water/seawater splitting. Characterizations displayed that TCP with an ultrahigh surface area can confine the agglomeration of PtCu alloy; meanwhile, the PtCu alloy can facilitate the rapid electron transfer from TCP. In addition, TCP with a stable covalent bond structure can resist the corrosion of seawater. Benefiting from these two advantages, Pt7Cu1-TCP showed a remarkably enhanced photocatalytic performance with a maximum H2 evolution rate of 3255 µmol g-1 h-1 in natural seawater with triethanolamine, which is 2.69, 116.25, and 1.08 times that of Pt-TCP, Cu-TCP, and optimal catalyst in pure water, respectively. This study provides an idea for the development of a novel catalytic system for hydrogen production from solar-driven water/seawater splitting.

Technical variety of anastomotic techniques used in proximal gastrectomy with double-tract-reconstruction - a narrative review.

In the past 40 years, the incidence of esophagogastric junction cancer has been gradually increasing worldwide. Currently, surgical resection remains the main radical treatment for early gastric cancer. Due to the rise of functional preservation surgery, proximal gastrectomy has become an alternative to total gastrectomy for surgeons in Japan and South Korea. However, the methods of digestive tract reconstruction after proximal gastrectomy have not been fully unified. At present, the principal methods include esophagogastrostomy, double flap technique, jejunal interposition, and double tract reconstruction. Related studies have shown that double tract reconstruction has a good anti-reflux effect and improves postoperative nutritional prognosis, and it is expected to become a standard digestive tract reconstruction method after proximal gastrectomy. However, the optimal anastomoses mode in current double tract reconstruction is still controversial. This article aims to review the current status of double tract reconstruction and address the aforementioned issues.

Characterising the motion and cardiorespiratory interaction of preterm infants can improve the classification of their sleep state.

AIM: This study aimed to classify quiet sleep, active sleep and wake states in preterm infants by analysing cardiorespiratory signals obtained from routine patient monitors. METHODS: We studied eight preterm infants, with an average postmenstrual age of 32.3 ± 2.4 weeks, in a neonatal intensive care unit in the Netherlands. Electrocardiography and chest impedance respiratory signals were recorded. After filtering and R-peak detection, cardiorespiratory features and motion and cardiorespiratory interaction features were extracted, based on previous research. An extremely randomised trees algorithm was used for classification and performance was evaluated using leave-one-patient-out cross-validation and Cohen's kappa coefficient. RESULTS: A sleep expert annotated 4731 30-second epochs (39.4 h) and active sleep, quiet sleep and wake accounted for 73.3%, 12.6% and 14.1% respectively. Using all features, and the extremely randomised trees algorithm, the binary discrimination between active and quiet sleep was better than between other states. Incorporating motion and cardiorespiratory interaction features improved the classification of all sleep states (kappa 0.38 ± 0.09) than analyses without these features (kappa 0.31 ± 0.11). CONCLUSION: Cardiorespiratory interactions contributed to detecting quiet sleep and motion features contributed to detecting wake states. This combination improved the automated classifications of sleep states.

Bta-miR-149-3p suppresses inflammatory response in bovine Sertoli cells exposed to microcystin-leucine arginine (MC-LR) through TLR4/NF-kB signaling pathway.

This study explored the regulatory role of bta-miR-149-3p in the inflammatory response induced by microcystin-leucine arginine (MC-LR) exposure in bovine Sertoli cells. The research endeavored to enhance the comprehension of the epigenetic mechanisms underlying MC-LR-induced cytotoxicity in Sertoli cells and establish a foundation for mitigating these effects in vitro. In this study, we elucidated the regulatory mechanism of bta-miR-149-3p in the MC-LR-induced inflammatory response by verifying the target gene of bta-miR-149-3p through luciferase assays and treating the cells with a bta-miR-149-3p inhibitor for 24 h. The results demonstrate that nuclear factor κB (NF-κB) acts as a downstream target gene of bta-miR-149-3p, which inhibits the MC-LR-induced inflammatory response in bovine Sertoli cells. This inhibition occurs by regulating the downregulation of tight junction constitutive proteins of the blood-testis barrier (BTB) through the suppression of the TLR-4/NF-κB signaling pathway (p < 0.05) and the up-regulation of the adhesion junction protein ß-catenin (p < 0.05). Notably, MC-LR exposure resulted in the up-regulation (p < 0.05) of inflammatory cytokines (IL-6, IL-1ß, and NLRP3) and the down-regulation (p < 0.05) of BTB tight junction constitutive proteins (ZO-1, Occludin) in Sertoli cells. Furthermore, the BTB constitutive protein ZO-1 exhibited significant down-regulation in Sertoli cells pretreated with the bta-miR-149-3p inhibitor compared to controls (p < 0.05), while Occludin showed no significant difference from CTNNB1 (p > 0.05). In summary, our findings suggest that bta-miR-149-3p suppresses the MC-LR-induced inflammatory response and alterations in the expression of BTB proteins in bovine Sertoli cells by inhibiting the TLR-4/NF-κB signaling pathway.

Metal-Organic Frameworks: Direct Synthesis by Organic Acid-Etching and Reconstruction Disclosure as Oxygen Evolution Electrocatalysts.

Metal-organic frameworks (MOFs) have emerged as promising oxygen evolution reaction (OER) electrocatalysts. Chemically bonded MOFs on supports are desirable yet lacking in routine synthesis, as they may allow variable structural evolution and the underlying structure-activity relationship to be disclosed. Herein, direct MOF synthesis is achieved by an organic acid-etching strategy (AES). Using π-conjugated ferrocene (Fc) dicarboxylic acid as the etching agent and organic ligand, a series of MFc-MOF (M=Ni, Co, Fe, Zn) nanosheets are synthesized on the metal supports. The crystal structure is studied using X-ray diffraction and low-dose transmission electron microscopy, which is quasi-lattice-matched with that of the metal, enabling in situ MOF growth. Operando Raman and attenuated total reflectance Fourier transform infrared spectroscopy disclose that the NiFc-MOF features dynamic structural rebuilding during OER. The reconstructed one showing optimized electronic structures with an upshifted total d-band center, high M-O bonding state occupancy, and localized electrons on adsorbates indicated by density functional theory calculations, exhibits outstanding OER performance with a fairly low overpotential (130 mV at 10 mA cm-2 ) and good stability (144 h). The newly established approach for direct MOF synthesis and structural reconstruction disclosure stimulate the development of more prudent catalysts for advancing OER.

Insights into Advanced Neurological Dysfunction Mechanisms Following DBS Surgery in Parkinson's Patients: Neuroinflammation and Pyroptosis.

Parkinson's disease is a severe neurodegenerative disorder. Currently, deep brain electrical stimulation (DBS) is the first line of surgical treatment. However, serious neurological impairments such as speech disorders, disturbances of consciousness, and depression after surgery limit the efficacy of treatment. In this review, we summarize the recent experimental and clinical studies that have explored the possible causes of neurological deficits after DBS. Furthermore, we tried to identify clues from oxidative stress and pathological changes in patients that could lead to the activation of microglia and astrocytes in DBS surgical injury. Notably, reliable evidence supports the idea that neuroinflammation is caused by microglia and astrocytes, which may contribute to caspase-1 pathway-mediated neuronal pyroptosis. Finally, existing drugs and treatments may partially ameliorate the loss of neurological function in patients following DBS surgery by exerting neuroprotective effects.

Hydrogen inhalation therapy regulates lactic acid metabolism following subarachnoid hemorrhage through the HIF-1α pathway.

The neuroprotective effects of hydrogen have been demonstrated, but the mechanism is still poorly understood. In a clinical trial of inhaled hydrogen in patients with subarachnoid hemorrhage (SAH), we found that hydrogen reduced the accumulation of lactic acid in the nervous system. There are no studies demonstrating the regulatory effect of hydrogen on lactate and in this study we hope to further clarify the mechanism by which hydrogen regulates lactate metabolism. In cell experiments, PCR and Western Blot showed that HIF-1α was the target related to lactic acid metabolism that changed the most before and after hydrogen intervention. HIF-1α levels were suppressed by hydrogen intervention treatment. Activation of HIF-1α inhibited the lactic acid-lowering effect of hydrogen. We have also demonstrated the lactic acid-lowering effect of hydrogen in animal studies. Our work clarifies that hydrogen can regulate lactate metabolism via the HIF-1αpathway, providing new insights into the neuroprotective mechanisms of hydrogen.

Optimization of fermentation conditions for surfactin production by B. subtilis YPS-32.

BACKGROUND: Surfactin produced by microbial fermentation has attracted increasing attention because of its low toxicity and excellent antibacterial activity. However, its application is greatly limited by high production costs and low yield. Therefore, it is important to produce surfactin efficiently while reducing the cost. In this study, B. subtilis strain YPS-32 was used as a fermentative strain for the production of surfactin, and the medium and culture conditions for the fermentation of B. subtilis YPS-32 for surfactin production were optimized. RESULTS: First, Landy 1 medium was screened as the basal medium for surfactin production by B. subtilis strain YPS-32. Then, using single-factor optimization, the optimal carbon source for surfactin production by B. subtilis YPS-32 strain was determined to be molasses, nitrogen sources were glutamic acid and soybean meal, and inorganic salts were KCl, K2HPO4, MgSO4, and Fe2(SO4)3. Subsequently, using Plackett-Burman design, MgSO4, time (h) and temperature (°C) were identified as the main effect factors. Finally, Box-Behnken design were performed on the main effect factors to obtain optimal fermentation conditions: temperature of 42.9 °C, time of 42.8 h, MgSO4 = 0.4 g·L- 1. This modified Landy medium was predicted to be an optimal fermentation medium: molasses 20 g·L- 1, glutamic acid 15 g·L- 1, soybean meal 4.5 g·L- 1, KCl 0.375 g·L- 1, K2HPO4 0.5 g·L- 1, Fe2(SO4)3 1.725 mg·L- 1, MgSO4 0.4 g·L- 1. Using the modified Landy medium, the yield of surfactin reached 1.82 g·L- 1 at pH 5.0, 42.9 ℃, and 2% inoculum for 42.8 h, which was 2.27-fold higher than that of the Landy 1 medium in shake flask fermentation. Additionally, under these optimal process conditions, further fermentation was carried out at the 5 L fermenter level by foam reflux method, and at 42.8 h of fermentation, surfactin reached a maximum yield of 2.39 g·L- 1, which was 2.96-fold higher than that of the Landy 1 medium in 5 L fermenter. CONCLUSION: In this study, the fermentation process of surfactin production by B. subtilis YPS-32 was improved by using a combination of single-factor tests and response surface methodology for test optimization, which laid the foundation for its industrial development and application.

93-THz ultra-broadband and ultra-low loss Y-junction photonic power splitter with phased inverse design.

Optical power splitters with ultra-broadband and ultra-low insertion loss are desired in the field of photonic integration. Combining two inverse design algorithms for staged optimization, we present the design of a Y-junction photonic power splitter with 700 nm wavelength bandwidth (from 1200 nm to 1900 nm) within a 0.2 dB insertion loss, corresponding to a 93 THz frequency bandwidth. The average insertion loss is approximately -0.057 dB in the valuable C-band. Moreover, we comprehensively compared the insertion loss performance of different types and sizes of curved waveguides, and also give the cases of 1:4 and 1:6 cascaded power splitters. These scalable Y-junction splitters provide new alternatives for high-performance photonic integration.

Three-dimensional mode-division multiplexing system.

Blindly increasing the channels of the mode (de)multiplexer on the single-layer chip can cause the device structure to be too complex to optimize. The three-dimensional (3D) mode division multiplexing (MDM) technology is a potential solution to extend the data capacity of the photonic integrated circuit by assembling the simple devices in the 3D space. In our work, we propose a 16 × 16 3D MDM system with a compact footprint of about 100 µm × 5.0 µm × 3.7 µm. It can realize 256 mode routes by converting the fundamental transverse electric (TE0) modes in arbitrary input waveguides into the expected modes in arbitrary output waveguides. To illustrate its mode-routing principle, the TE0 mode is launched in one of the sixteen input waveguides, and converted into corresponding modes in four output waveguides. The simulated results indicate that the ILs and CTs of the 16 × 16 3D MDM system are less than 3.5 dB and lower than -14.2 dB at 1550 nm, respectively. In principle, the 3D design architecture can be scaled to realize arbitrary network complexity levels.

P38-DAPK1 axis regulated LC3-associated phagocytosis (LAP) of microglia in an in vitro subarachnoid hemorrhage model.

BACKGROUND: The phagocytosis and homeostasis of microglia play an important role in promoting blood clearance and improving prognosis after subarachnoid hemorrhage (SAH). LC3-assocaited phagocytosis (LAP) contributes to the microglial phagocytosis and homeostasis via autophagy-related components. With RNA-seq sequencing, we found potential signal pathways and genes which were important for the LAP of microglia. METHODS: We used an in vitro model of oxyhemoglobin exposure as SAH model in the study. RNA-seq sequencing was performed to seek critical signal pathways and genes in regulating LAP. Bioparticles were used to access the phagocytic ability of microglia. Western blot (WB), immunoprecipitation, quantitative polymerase chain reaction (qPCR) and immunofluorescence were performed to detect the expression change of LAP-related components and investigate the potential mechanisms. RESULTS: In vitro SAH model, there were increased inflammation and decreased phagocytosis in microglia. At the same time, we found that the LAP of microglia was inhibited in all stages. RNA-seq sequencing revealed the importance of P38 MAPK signal pathway and DAPK1 in regulating microglial LAP. P38 was found to regulate the expression of DAPK1, and P38-DAPK1 axis was identified to regulate the LAP and homeostasis of microglia after SAH. Finally, we found that P38-DAPK1 axis regulated expression of BECN1, which indicated the potential mechanism of P38-DAPK1 axis regulating microglial LAP. CONCLUSION: P38-DAPK1 axis regulated the LAP of microglia via BECN1, affecting the phagocytosis and homeostasis of microglia in vitro SAH model. Video Abstract.

Transcriptomics and Phenotypic Analysis of gpr56 Knockout in Zebrafish.

The adhesion G-protein-coupled receptor is a seven-transmembrane receptor protein with a complex structure. Impaired GPR56 has been found to cause developmental damage to the human brain, resulting in intellectual disability and motor dysfunction. To date, studies on gpr56 deficiency in zebrafish have been limited to the nervous system, and there have been no reports of its systemic effects on juvenile fish at developmental stages. In order to explore the function of gpr56 in zebrafish, the CRISPR/Cas9 gene-editing system was used to construct a gpr56-knockout zebrafish. Subsequently, the differentially expressed genes (DEGs) at the transcriptional level between the 3 days post fertilization (dpf) homozygotes of the gpr56 mutation and the wildtype zebrafish were analyzed via RNA-seq. The results of the clustering analysis, quantitative PCR (qPCR), and in situ hybridization demonstrated that the expression of innate immunity-related genes in the mutant was disordered, and multiple genes encoding digestive enzymes of the pancreatic exocrine glands were significantly downregulated in the mutant. Motor ability tests demonstrated that the gpr56-/- zebrafish were more active, and this change was more pronounced in the presence of cold and additional stimuli. In conclusion, our results revealed the effect of gpr56 deletion on the gene expression of juvenile zebrafish and found that the gpr56 mutant was extremely active, providing an important clue for studying the mechanism of gpr56 in the development of juvenile zebrafish.

Engineered acetaldehyde dehydrogenase for the efficient degradation of acetaldehyde.

Acetaldehyde is highly cytotoxic and widely presents in food and the environment. Aldehyde dehydrogenase (ALDH) can degrade acetaldehyde to non-toxic acetic acid, showing potential for acetaldehyde elimination. However, a lack of high-throughput methods for screening efficient variants is a significant obstacle to ALDH design. Here, we established a visualized high-throughput method to screen recombinantly expressed ALDH variants in Bacillus subtilis by fluorescent probes of dual-acceptor cyanine-based in response to NADH, the acetaldehyde degradation product. Molecular docking revealed key amino acids in the binding region of acetaldehyde to ALDH. Combined with saturation mutagenesis and visualization high-throughput methods, a variant ALDHS273N with an activity of 119.82 U·mL-1 was screened. The optimal reaction temperature and pH of ALDHS273N were 60 °C and 9.0, respectively. ALDHS273N showed stability at 30-50 °C and pH 5.0-9.0. The activity of ALDHS273N was increased to 263.52 U∙mL-1 by fermentation optimization, which was 5.58 times that of ALDHWT. The degradation rate of ALDHS273N to 100 mmol L-1 acetaldehyde was 87.34% within 2 h, which was 4.2 times that of the wild enzyme (20.81%). As far as we know, this is the ALDH with the highest activity reported so far, and it is also the first time that ALDH has been used for the efficient degradation of acetaldehyde. Overall, the reported high-throughput screening method and developed mutants represent a significant advance in green bio-elimination technologies of acetaldehyde.

The Effect of Psychological Intervention on the Visual Quality of Patients with a Diffractive Multifocal Intraocular Lens Implant.

OBJECTIVE: This study aimed to investigate the effect of psychological intervention on the visual quality of patients with a diffractive multifocal intraocular lens implant and its possible mechanism. METHODS: Eighty-nine patients undergoing age-related cataract surgery were enrolled in the study at the Affiliated Hospital of Southwest Medical University between December 2015 and July 2017. They were randomly divided into two groups: multiple focus M1 group (n = 45) and multiple focus M2 group (n = 40). The M1 group was only given routine preoperative health education, treatment, and evaluation, while the M2 group also received psychological intervention. RESULTS: After treatment, there was no statistical difference in the uncorrected distance and near visual acuity, corrected distance and near visual acuity, or the vision and near removal rate in either of the two groups (p > 0.05). However, postoperative glare was lower in the M2 group (p < 0.05), and patient satisfaction was higher in the M2 group (p < 0.05). The M2 group had a more obvious improvement in the Symptom Checklist-90 score (p < 0.05), the serum interleukin-6 (IL-6) was lower, and the serum brain-derived neurotrophic factor (BDNF) was higher in the M2 group (p < 0.05). In addition, serum IL-6 had a negative correlation with the depression score, and serum BDNF also showed a negative correlation with the anxiety score (p < 0.05). CONCLUSIONS: Psychological intervention improved the stress state of patients with age-related cataracts and diffractive multifocal intraocular lens implants, reduced the level of inflammatory factors in the body, improved the level of BDNF, reduced postoperative visual interference, and improved postoperative satisfaction.

Continued P2X7 activation leads to mitochondrial fission and compromising microglial phagocytosis after subarachnoid haemorrhage.

Subarachnoid haemorrhage (SAH) has a high rate of disability and mortality. Extremely damaging molecules, including adenosine triphosphate (ATP), are released from extravasated red blood cells and nerve cells, which activate microglia and induce sterile tissue injury and organ dysfunction. P2X purinoceptor 7 (P2X7) is one of the most important purine receptors on the microglial surface and is involved in the proinflammatory activation of microglia. While P2X7 can also affect microglial phagocytosis, the mechanism is not clear. Here, we demonstrated that microglial phagocytosis is progressively impaired under continued BzATP exposure and P2X7 activation. Furthermore, we found that P2X7 activation leads to increased intracellular Ca2+ levels and activates Calcineurin, which dephosphorylates dynamin-related protein 1 (DRP1) S637. The dephosphorylation of DRP1 at S637 leads to increased mitochondrial fission and decreased mitochondrial function, which may be responsible for the decreased microglial phagocytosis. Finally, we pharmacologically inhibited P2X7 activation in mice, which resulted in rescue of mitochondrial function and decreased microglial proliferation, but improved phagocytosis after SAH. Our study confirmed that P2X7 activation after SAH leads to the impairment of microglial phagocytosis through mitochondrial fission and verified that P2X7 inhibition restores microglial phagocytosis both in vitro and in vivo.

Profiling the role of microorganisms in quality improvement of the aged flue-cured tobacco.

BACKGROUND: The aging process in the tobacco production, as in other food industries, is an important process for improving the quality of raw materials. In the spontaneous aging, the complex components in flue-cured tobacco (FT) improve flavor or reduce harmful compounds through chemical reactions, microbial metabolism, and enzymatic catalysis. Some believed that tobacco-microbe played a significant part in this process. However, little information is available on how microbes mediate chemical composition to improve the quality of FT, which will lay the foundation for the time-consuming spontaneous aging to seek ways to shorten the aging cycle. RESULTS: Comparing aged and unaged FT, volatile and non-volatile differential compounds (DCs) were multi-dimensionally analyzed with the non-targeted metabolomes based on UPLC-QTOP-MS (the ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry), GC-MS (gas chromatography-mass spectrometer) assisted derivatization and HP-SPME-GC/MS (headspace solid-phase micro-extraction assisted GC-MS). Products associated with the degradation pathways of terpenoids or higher fatty acids were one of the most important factors in improving FT quality. With the microbiome, the diversity and functions of microbial flora were analyzed. The high relative abundance function categories were in coincidence with DCs-related metabolic pathways. According to the correlation analysis, Acinetobacter, Sphingomonas and Aspergillus were presumed to be the important contributor, in which Aspergillus was associated with the highest number of degradation products of terpenoids and higher fatty acids. At last, the screened Aspergillus nidulans strain F4 could promote the degradation of terpenoids and higher fatty acids to enhance tobacco flavor by secreting highly active lipoxygenase and peroxidase, which verified the effect of tobacco-microbes on FT quality. CONCLUSIONS: By integrating the microbiome and metabolome, tobacco-microbe can mediate flavor-related substances to improve the quality of FT after aging, which provided a basis for identifying functional microorganisms for reforming the traditional spontaneous aging.

Manipulation force analysis of nanoparticles with ultra-high numerical aperture metalens.

Metalens optical tweezers technology has several advantages for manipulating micro-nano particles and high integration. Here, we used particle swarm optimization (PSO) to design a novel metalens tweezer, which can get 3-dimensional trapping of particles. The numerical aperture (NA) of the metalens can reach 0.97 and the average focusing efficiency is 44%. Subsequently, we analyzed the optical force characteristics of SiO2 particles with a radius of 350 nm at the focal point of the achromatic metalens. We found the average maximum force of SiO2 particles in the x-direction and z-direction to be 0.88 pN and 0.72 pN, respectively. Compared with the dispersive metalens, it is beneficial in maintaining the constant of optical force, the motion state of trapped particles, and the stability of the trapping position.

Series of ultra-low loss and ultra-compact multichannel silicon waveguide crossing.

Ultra-compact waveguide crossing (UC-WC) is a basic component in optoelectronic fusion chip solutions, as its footprint is smaller in the orders of magnitude than that of traditional photonic integrated circuits (PICs). However, a large loss of UC-WC (decibel level) becomes a barrier to scaling and practicality. Here, we propose a series of ultra-low loss UC-WC silicon devices using an advanced hybrid design that combines the adjoint method with the direct binary search (DBS) algorithm. Simulation results show that our 2 × 2 UC-WC has an insertion loss as low as 0.04 dB at 1550 nm, which is about ten times lower than the previous UC-WC results. In the valuable C-band (1530-1565 nm), the insertion loss of UC-WC is lower than -0.05 dB, and the channel crosstalk is lower than -34 dB. Furthermore, for the 3 × 3 UC-WC device, the highest insertion loss in the entire C-band is approximately -0.07 dB, and the highest channel crosstalk is lower than -33 dB. Additionally, the 4 × 4 and more complex 8 × 8 UC-WC devices were also analyzed. The highest insertion loss for 4 × 4 and 8 × 8 UC-WC in the C-band is only -0.19 dB and -0.20 dB, respectively, and the highest channel crosstalk is approximately -22dB and -28 dB, respectively. These results confirm that the designed devices possess two attractive features simultaneously: ultra-compactness and ultra-low insertion loss, which may be of great value in future large-scale optoelectronic fusion chips.

Metabolite-based cell sorting workflow for identifying microbes producing carbonyls in tobacco leaves.

Carbonyl compounds represented by aldehydes and ketones make an important contribution to the flavor of tobacco. Since most carbonyl compounds are produced by microbes during tobacco fermentation, identifying their producers is important to improve the quality of tobacco. Here, we created an efficient workflow that combines metabolite labeling with fluorescence-activated cell sorting (ML-FACS), 16S rRNA gene sequencing, and microbial culture to identify the microbes that produce aldehydes or ketones in fermented cigar tobacco leaves (FCTL). Microbes were labeled with a specific fluorescent dye (cyanine5 hydrazide) and separated by flow cytometry. Subsequently, the sorted microbes were identified and cultured under laboratory conditions. Four genera, Acinetobacter, Sphingomonas, Solibacillus, and Lysinibacillus, were identified as the main carbonyl compound-producing microbes in FCTL. In addition, these microorganisms could produce flavor-related aldehydes and ketones in a simple synthetic medium, such as benzaldehyde, phenylacetaldehyde, 4-hydroxy-3-ethoxy-benzaldehyde, and 3,5,5-trimethyl-2-cyclohexene-1-one. On the whole, this research has developed a new method to quickly isolate and identify microorganisms that produce aldehydes or ketones from complex microbial communities. ML-FACS would also be used to identify other compound-producing microorganisms in other systems. KEY POINTS: • An approach was developed to identify target microbes in complex communities. • Microbes that produce aldehyde/ketone flavor compounds in fermented cigar tobacco leaves were identified. • Functional microbes that produce aldehyde/ketone flavor compounds from the native environment were captured in pure cultures.