Observation and quantification of the pseudogap in unitary Fermi gases.

The microscopic origin of high-temperature superconductivity in cuprates remains unknown. It is widely believed that substantial progress could be achieved by better understanding of the pseudogap phase, a normal non-superconducting state of cuprates1,2. In particular, a central issue is whether the pseudogap could originate from strong pairing fluctuations3. Unitary Fermi gases4,5, in which the pseudogap-if it exists-necessarily arises from many-body pairing, offer ideal quantum simulators to address this question. Here we report the observation of a pair-fluctuation-driven pseudogap in homogeneous unitary Fermi gases of lithium-6 atoms, by precisely measuring the fermion spectral function through momentum-resolved microwave spectroscopy and without spurious effects from final-state interactions. The temperature dependence of the pairing gap, inverse pair lifetime and single-particle scattering rate are quantitatively determined by analysing the spectra. We find a large pseudogap above the superfluid transition temperature. The inverse pair lifetime exhibits a thermally activated exponential behaviour, uncovering the microscopic virtual pair breaking and recombination mechanism. The obtained large, temperature-independent single-particle scattering rate is comparable with that set by the Planckian limit6. Our findings quantitatively characterize the pseudogap in strongly interacting Fermi gases and they lend support for the role of preformed pairing as a precursor to superfluidity.

Phylogeny and adaptive evolution of subgenus Rhizirideum (Amaryllidaceae, Allium) based on plastid genomes.

The subgenus Rhizirideum in the genus Allium consists of 38 species worldwide and forms five sections (A. sect. Rhizomatosa, A. sect. Tenuissima, A. sect. Rhizirideum, A. sect. Eduardia, and A. sect. Caespitosoprason), A. sect. Caespitosoprason being merged into A. sect. Rhizomatosa recently. Previous studies on this subgenus mainly focused on separate sections. To investigate the inter-section and inter-subgenera phylogenetic relationships and adaptive evolution of A. subg. Rhizirideum, we selected thirteen representative species, which cover five sections of this subgenus and can represent four typical phenotypes of it. We conducted the comparative plastome analysis with our thirteen plastomes. And phylogenetic inferences with CDSs and complete sequences of plastomes of our thirteen species and another fifty-four related species were also performed. As a result, the A. subg. Rhizirideum plastomes were relatively conservative in structure, IR/SC borders, codon usage, and repeat sequence. In phylogenetic results, the inter-subgenera relationships among A. subg. Rhizirideum and other genus Allium subgenera were generally similar to the previous reports. In contrast, the inter-section relationships within our subgenus A. subg. Rhizirideum were newly resolved in this study. A. sect. Rhizomatosa and A. sect. Tenuissima were sister branches, which were then clustered with A. sect. Rhizirideum and A. sect. Eduardia successively. However, Allium Polyrhizum Turcz. ex Regel, type species of A. sect. Caespitosoprason, was resolved as the basal taxon of A. subg. Rhizirideum. Allium siphonanthum J. M. Xu was also found in clade A. subg. Cyathophora instead of clade A. subg. Rhizirideum. The selective pressure analysis was also conducted, and most protein-coding genes were under purifying selection. At the same time, just one gene, ycf2, was found under positive selection, and another three genes (rbcL, ycf1a, ycf1b) presented relaxed selection, which were all involved in the photosynthesis. The low temperature, dry climate, and high altitude of the extreme habitats where A. subg. Rhizirideum species grow might impose intense natural selection forces on their plastome genes for photosynthesis. In summary, our research provides new insights into the phylogeny and adaptive evolution of A. subg. Rhizirideum. Moreover, we suggest that the positions of the A. subg. Rhizirideum species A. polyrhizum and A. siphonanthum should be reconsidered.

Care patterns and Traditional Chinese Medicine constitution as factors of depression and anxiety in patients with systemic sclerosis: A cross-sectional study during the COVID-19 pandemic.

Objective: Care patterns and Traditional Chinese Medicine (TCM) constitution affects the emotion and health of patients with systemic sclerosis (SSc) while the prevalence of COVID-19 may aggravate such patients' emotion and health. We investigated the depression and anxiety levels of patients with SSc during the pandemic to identify the correlation between care patterns, TCM constitution, and patients' emotion. Materials and methods: This was a cross-sectional study. Patients with SSc and healthy individuals were surveyed using the patient health questionnaire-9, generalized anxiety disorder-7, and constitution in Chinese medicine questionnaire and a modified care pattern questionnaire. Factors correlated with depression and anxiety were screened using univariate and multivariate logistic regression analyses. Results: A total of 273 patients with SSc and 111 healthy individuals were included in the analysis. The proportion of patients with SSc who were depressed was 74.36%, who had anxiety was 51.65%, and who experienced disease progression during the pandemic was 36.99%. The proportion of income reduction in the online group (56.19%) was higher than that in the hospital group (33.33%) (P = 0.001). Qi-deficiency [adjusted odds ratio (OR) = 2.250] and Qi-stagnation (adjusted OR = 3.824) constitutions were significantly associated with depression. Remote work during the outbreak (adjusted OR = 1.920), decrease in income (adjusted OR = 3.556), and disease progression (P = 0.030) were associated with the occurrence of depression. Conclusion: Chinese patients with SSc have a high prevalence of depression and anxiety. The COVID-19 pandemic has changed the care patterns of Chinese patients with SSc, and work, income, disease progression, and change of medications were correlates of depression or anxiety in patients with SSc. Qi-stagnation and Qi-deficiency constitutions were associated with depression, and Qi-stagnation constitution was associated with anxiety in patients with SSc. Trial registration: http://www.chictr.org.cn/showproj.aspx?proj=62301, identifier ChiCTR2000038796.

Coordination effect enhanced visualization of latent fingerprint with Eu (TTA)3phen-SiO2 microspheres.

Latent fingerprint (LFP) powders are crucial in the detection of LFPs in forensic science. However, it is often plagued by poor image resolution and low contrast. Herein, enhanced LFP fluorescence (FL) visualizations are achieved by doping Eu(III) coordination compound Eu(TTA)3phen directly into SiO2 microspheres instead of Eu(III) ions. Using the synthesized Eu(TTA)3phen-SiO2 microspheres, the fine characteristic structure of LFP can be seen and recognized under 365 nm irradiation, up to Level 3. However, the Eu3+-SiO2 microspheres were difficult to recognize the Level 2,3 fingerprint structure. The difference between the ridge and furrow gray values of Eu(TTA)3phen-SiO2 microspheres is 2.1 times that of Eu3+-SiO2 microspheres. The coordination effect increased the asymmetry around Eu(III) ions, resulting in the ultrasensitive 5D0→7F2 transition, thus increasing the FL intensity, and the uniform doping of the Eu(III) coordination compound into SiO2 also reduced the surface FL quenching due to shielding from oxygen. Under this dual effect, the LFP performance of Eu(TTA)3phen-SiO2 microspheres has been significantly improved. We believe that this novel and easy LFP visualization method is a promising routine in specific target detection including criminal investigation, customhouse check-in, and drug control.

[Preparation of rat model of systemic inflammatory response syndrome induced by zymosan].

OBJECTIVE: To establish a model of systemic inflammatory response syndrome (SIRS) in rats. METHODS: SD rats were intraperitoneally injected with different concentrations of zymosan suspension. The general status, temperature, white cell count, tumor necrosis factor-α(TNF-α), interleukin-6(IL-6), interleukin-10 (IL-10) and the pathological changes of main organs were examined. RESULTS: The conditions of rats receiving zymosan doses of 750 mg/kg and 1000 mg/kg were consistent with the criteria of SIRS model; however, the mortality of 1000 mg/kg group was higher than that of 750 mg/kg group. CONCLUSION: The rat model of systemic inflammatory response syndrome has been successfully induced.

Efficient NIR electrochemiluminescent dyes based on ruthenium(II) complexes containing an N-heterocyclic carbene ligand.

Three new ruthenium(ii) complexes containing an N-heterocyclic carbene (NHC) ligand (RuNHC) have been successfully synthesized and proved to be efficient near-infrared (NIR) ECL (electrogenerated chemiluminescence) luminophores. In addition to the advantages of the lower-charge main motif (+1), the much lower oxidation potentials, and the longer metal to ligand charge transfer (MLCT) absorption bands, most importantly, these RuNHC complexes show higher, or at least comparable, ECL efficiency compared with Ru(bpy)32+ under the same experimental conditions; this demonstrates their great potential for applications in the NIR ECL imaging field in the future.

[Hepatitis B virus X protein regulates c-met promoter via the ERKs singal pathway in HepG2 cells].

OBJECTIVE: To explore the signal pathway mediating the regulatory effect of Hepatitis B virus X protein (HBX) on c-met gene promoter in HepG2 cells. METHODS: The expression of c-met in HBX-transfected HepG2 cells treated with different signal pathway inhibitors was detected by western blot, the invasion capability of cells was determined by Matrigel invasion assay. RESULTS: ERK inhibitor U0126 inhibited the expression of the c-Met in HBx-transfected HepG2 cells. However, both p38MAPK inhibitor SB203580 and PI-3K inhibitor wortmanin had no effect on expression of the c-Met in HBx-transfected HepG2 cells. Furthermore, the ERK inhibitor U0126 also inhibited the invasiveness of HBX-transfected HepG2 cells. CONCLUSION: HBx induces invasion of HCC via activation of ERK pathway.

Vagal Nerve Stimulation Attenuates Ischemia-Reperfusion Induced Retina Dysfunction in Acute Ocular Hypertension.

Purpose: The present study aimed to investigate whether cervical vagal nerve stimulation (VNS) could prevent retinal ganglion cell (RGC) loss and retinal dysfunction after ischemia/reperfusion (I/R) injury. Methods: First, rats were randomly divided into sham group (n = 4) and VNS group (n = 12). Activation of the nodose ganglia (NOG), nucleus of the solitary tract (NTS), superior salivatory nucleus (SSN), and pterygopalatine ganglion (PPG) neural circuit were evaluated by c-fos expression at 0 h after sham VNS and at 0 h (n = 4), 6 h (n = 4), 72 h (n = 4) after VNS. Secondly, rats were randomly assigned to I/R group (pressure-induced retinal ischemia for 1 h and reperfusion for 1 h in the right eye, n = 16) and I/R+VNS group (right cervical VNS for 2 h during the I/R period, n = 16). The left eye of each rat served as a control. Electroretinogram (ERG), RGC numbers, tumor necrosis factor-α (TNF-α) and vasoactive intestinal polypeptide (VIP) levels in retina were determined. Additionally, the level of VIP in PPG was evaluated. Results: In the first part of the study, compared with the sham group, the VNS group exhibited significantly increased expression of c-fos in NOG, NTS, SSN, and PPG tissues at 0, 6, and 72 h. In the second part of the study, compared with left eyes, retinal function in right eyes (as assessed by the a-wave, b-wave and the oscillatory potential amplitudes of ERG and RGC data) was significantly decreased by I/R. The decreased retinal function was attenuated by VNS. In addition, I/R induced an increase in inflammation, which was reflected by elevated TNF-α expression in the retina. VNS significantly attenuated the increase in I/R-induced inflammation. Moreover, VIP expression in the retina and PPG, which may contribute to the inhibition of the inflammatory response, was significantly increased after VNS. Conclusion: VNS could protect against retinal I/R injury by downregulating TNF-α. Upregulation of VIP expression due to activation of the NOG-NTS-SSN-PPG neural circuit may underlie to the protective effects of VNS.

Promising Compounds From Murraya exotica for Cancer Metastasis Chemoprevention.

Most of the present anticancer drugs are highly cytotoxic and focus mainly on killing tumor cells rather than slowing the progress of cancer metastasis. Evidence has been reported that bridges the mechanisms of inflammation and tumor invasion. Therefore, we evaluated the potency in cancer metastasis chemoprevention of compounds and a coumarin extracted from Murraya exotica, which is known for its anti-inflammation bioactivity. By carrying out experiments in vitro, we found the root extracts more efficient than the leaf extracts in restraining cell migration of MDA-MB-231 cells, while leaf extracts presented slightly stronger inhibition of tumor cell adhesion at low concentrations. In addition, compared to root extracts, a novel coumarin identified previously from root extracts showed equal inhibition on cancer cell adhesion and less inhibition on cell migration. All extracts used in this study presented low cytotoxicity in vitro. Through comparison of the contents of leaf and root extracts from M exotica, several compounds are considered promising against cancer metastasis. This study evaluates the worth of further development of M exotica to find its effect on cancer metastasis chemoprevention.

Biodegradation kinetics of tetrahydrofuran, benzene, toluene, and ethylbenzene as multi-substrate by Pseudomonas oleovorans DT4.

The biodegradation kinetics of tetrahydrofuran, benzene (B), toluene (T), and ethylbenzene (E) were systematically investigated individually and as mixtures by a series of aerobic batch degradation experiments initiated by Pseudomonas oleovorans DT4. The Andrews model parameters, e.g., maximum specific growth rates (µmax), half saturation, and substrate inhibition constant, were obtained from single-substrate experiments. The interaction parameters in the sum kinetics model (SKIP) were obtained from the dual substrates. The µmax value of 1.01 for tetrahydrofuran indicated that cell growth using tetrahydrofuran as carbon source was faster than the growth on B (µmax, B = 0.39) or T (µmax, T = 0.39). The interactions in the dual-substrate experiments, including genhancement, inhibition, and co-metabolism, in the mixtures of tetrahydrofuran with B or T or E were identified. The degradation of the four compounds existing simultaneously could be predicted by the combination of SKIP and co-metabolism models. This study is the first to quantify the interactions between tetrahydrofuran and BTE.

Substrate interactions during the biodegradation of BTEX and THF mixtures by Pseudomonas oleovorans DT4.

The efficient tetrahydrofuran (THF)-degrading bacterium, Pseudomonas oleovorans DT4 was used to investigate the substrate interactions during the aerobic biotransformation of THF and BTEX mixtures. Benzene and toluene could be utilized as growth substrates by DT4, whereas cometabolism of m-xylene, p-xylene and ethylbenzene occurred with THF. In binary mixtures, THF degradation was delayed by xylene, ethylbenzene, toluene and benzene in descending order of inhibitory effects. Conversely, benzene (or toluene) degradation was greatly enhanced by THF leading to a higher degradation rate of 39.68 mg/(h g dry weight) and a shorter complete degradation time about 21 h, possibly because THF acted as an "energy generator". Additionally, the induction experiments suggested that BTEX and THF degradation was initiated by independent and inducible enzymes. The transient intermediate hydroquinone was detected in benzene biodegradation with THF while catechol in the process without THF, suggesting that P. oleovorans DT4 possessed two distinguished benzene pathways.

[Characteristics of tetrahydrofuran degradation by Pseudomonas oleovorans DT4].

A tetrahydrofuran (THF)-degrading strain Pseudomonas oleovorans DT4 was isolated from the activated sludge of a pharmaceutical plant. P. oleovorans DT4 was able to utilize THF as the sole carbon and energy source under aerobic condition. 5 mmol/L of THF could be completely degraded by 3.2 mg/L inoculums of P. oleovorans DT4 in 14 h at pH 7.2 and 30 degrees C, with the cells concentration increasing to 188.6 mg/L. After the complete consumption of THF, no TOC could be detected but IC reached the stable value of about 46 mg/L, with pH decreasing to 6.54, which indicated that the substance was totally mineralized by P. oleovorans DT4. The optimum conditions for THF biodegradation in shaking flasks were pH 7.5 and temperature 37 degrees C, respectively. Results from the oxygen control experiments revealed that the oxygen supply by shaking was the satisfactory growth condition. Additionally, as the important elements for DT4, Mg2+ and Ca2+ at concentrations of 0.80 mmol/L and 0.20 mmol/L, respectively, were suitable for THF degradation. All the results contribute to the efficient bioremediation for the THF contaminated.

A newly isolated strain capable of effectively degrading tetrahydrofuran and its performance in a continuous flow system.

A Gram-negative strain DT4, capable of growing aerobically on tetrahydrofuran (THF) as the sole carbon and energy source was isolated from a pharmaceutical wastewater treatment plant. It was identified as Pseudomonas oleovorans by morphological and physiological characteristics as well as Biolog profiling and 16S rDNA sequence. Cells of P. oleovorans DT4 pre-cultured in THF could degrade 5 mM THF completely without lag phase. The generation time of 2.7 h and the maximum degradation rate of 203.9 mg THF/(h g dry weight) were observed, demonstrating that DT4 bears the highest THF-degrading activity in ever described strains. Furthermore, THF concentration as high as 100 mM was tolerated by the culture. Several important compounds including gamma-butyrrolactone and benzene could be directly metabolized, whereas other pollutants (e.g., tetrahydropyrane) could be cometabolized by DT4. THF removal was achieved in a continuous flow system with the maximum specific growth rate 0.113 h(-1) and half-saturation constant 1.224 mg/L, indicating the great potential of THF bioremediation in future full-scale application.