Unnatural Amino Acids for Biological Spectroscopy and Microscopy.

Due to advances in methods for site-specific incorporation of unnatural amino acids (UAAs) into proteins, a large number of UAAs with tailored chemical and/or physical properties have been developed and used in a wide array of biological applications. In particular, UAAs with specific spectroscopic characteristics can be used as external reporters to produce additional signals, hence increasing the information content obtainable in protein spectroscopic and/or imaging measurements. In this Review, we summarize the progress in the past two decades in the development of such UAAs and their applications in biological spectroscopy and microscopy, with a focus on UAAs that can be used as site-specific vibrational, fluorescence, electron paramagnetic resonance (EPR), or nuclear magnetic resonance (NMR) probes. Wherever applicable, we also discuss future directions.

Highly restricted near-surface permafrost extent during the mid-Pliocene warm period.

Accurate understanding of permafrost dynamics is critical for evaluating and mitigating impacts that may arise as permafrost degrades in the future; however, existing projections have large uncertainties. Studies of how permafrost responded historically during Earth's past warm periods are helpful in exploring potential future permafrost behavior and to evaluate the uncertainty of future permafrost change projections. Here, we combine a surface frost index model with outputs from the second phase of the Pliocene Model Intercomparison Project to simulate the near-surface (~3 to 4 m depth) permafrost state in the Northern Hemisphere during the mid-Pliocene warm period (mPWP, ~3.264 to 3.025 Ma). This period shares similarities with the projected future climate. Constrained by proxy-based surface air temperature records, our simulations demonstrate that near-surface permafrost was highly spatially restricted during the mPWP and was 93 ± 3% smaller than the preindustrial extent. Near-surface permafrost was present only in the eastern Siberian uplands, Canadian high Arctic Archipelago, and northernmost Greenland. The simulations are similar to near-surface permafrost changes projected for the end of this century under the SSP5-8.5 scenario and provide a perspective on the potential permafrost behavior that may be expected in a warmer world.

KCNH6 is essential for insulin secretion by regulating intracellular ER Ca2+ store.

Appropriate Ca2+ concentration in the endoplasmic reticulum (ER), modulating cytosolic Ca2+ signal, serves significant roles in physiological function of pancreatic ß cells. To maintaining ER homeostasis, Ca2+ movement across the ER membrane is always accompanied by a simultaneous K+ flux in the opposite direction. KCNH6 was proven to modulate insulin secretion by controlling plasma membrane action potential duration and intracellular Ca2+ influx. Meanwhile, the specific function of KCNH6 in pancreatic ß-cells remains unclear. In this study, we found that KCNH6 exhibited mainly ER localization and Kcnh6 ß-cell-specific knockout (ßKO) mice suffered from abnormal glucose tolerance and impaired insulin secretion in adulthood. ER Ca2+ store was overloaded in islets of ßKO mice, which contributed to ER stress and ER stress-induced apoptosis in ß cells. Next, we verified that ethanol treatment induced increases in ER Ca2+ store and apoptosis in pancreatic ß cells, whereas adenovirus-mediated KCNH6 overexpression in islets attenuated ethanol-induced ER stress and apoptosis. In addition, tail-vein injections of KCNH6 lentivirus rescued KCNH6 expression in ßKO mice, restored ER Ca2+ overload and attenuated ER stress in ß cells, which further confirms that KCNH6 protects islets from ER stress and apoptosis. These data suggest that KCNH6 on the ER membrane may help to stabilize intracellular ER Ca2+ stores and protect ß cells from ER stress and apoptosis. In conclusion, our study reveals the protective potential of KCNH6-targeting drugs in ER stress-induced diabetes.

Social media promotion, risk perception, and parental support for adolescent girls' HPV vaccination: Taking consideration of future consequences and sexual attitudes as moderators.

HPV vaccine hesitancy in Asia is unique compared to western countries. Concerning whether social media promotion about HPV vaccine will be related with parental support for Chinese adolescent girls, we investigated the correlation among social media promotion, risk perception of HPV vaccine and parental support. Through the theoretical lens of Health Action Process Approach model (HAPA), we found that social media promotion could reduce the risk perception of HPV vaccine and promoted parental supportive decision, and risk perception played a mediation role between social media information exposure to vaccine and parental support. Consideration of future consequences has been found to play a moderating role between social media promotion and risk perception, and parents' sexual attitudes moderated the effect of social media promotion on parental support. Implications of the findings are discussed.

The natural compound Sanggenon C inhibits PRRSV infection by regulating the TRAF2/NF-κB signalling pathway.

Porcine reproductive and respiratory syndrome (PRRS) is a serious infectious disease and one of the major causes of death in the global pig industry. PRRS virus (PRRSV) strains have complex and diverse genetic characteristics and cross-protection between strains is low, which complicates vaccine selection; thus, the current vaccination strategy has been greatly compromised. Therefore, it is necessary to identify effective natural compounds for the clinical treatment of PRRS. A small molecule library composed of 720 natural compounds was screened in vitro, and we found that Sanggenon C (SC) was amongst the most effective natural compound inhibitors of PRRSV infection. Compared with ribavirin, SC more significantly inhibited PRRSV infection at both the gene and protein levels and reduced the viral titres and levels of protein expression and inflammatory cytokine secretion to more effectively protect cells from PRRSV infection and damage. Mechanistically, SC inhibits activation of the NF-κB signalling pathway by promoting TRAF2 expression, thereby reducing PRRSV replication. In conclusion, by screening natural compounds, we found that SC suppresses PRRSV infection by regulating the TRAF2/NF-κB signalling pathway. This study contributes to a deeper understanding of the therapeutic targets and pathogenesis of PRRSV infection. More importantly, our results demonstrate that SC has potential as a candidate for the treatment of PRRS.

Quantum mechanics/molecular mechanics studies on the excited-state decay mechanisms of cytidine aza-analogues: 5-azacytidine and 2'-deoxy-5-azacytidine in aqueous solution.

The excited state properties and deactivation pathways of two DNA methylation inhibitors, i.e., 5-azacytidine (5ACyd) and 2'-deoxy-5-azacytidine (5AdCyd) in aqueous solution, are comprehensively explored with the QM(CASPT2//CASSCF)/MM protocol. We systematically map the feasible decay mechanisms based on the obtained excited-state decay paths involving all the identified minimum-energy structures, conical intersections, and crossing points driving the different internal conversion (IC) and intersystem crossing (ISC) routes in and between the 1ππ*, 1nπ*, 3ππ*, 3nπ*, and S0 states. Unlike the 1nπ* state below the 1ππ* state in 5ACyd, deoxyribose group substitution at the N1 position leads to the 1ππ* state becoming the S1 state in 5AdCyd. In 5ACyd and 5AdCyd, the initially populated 1ππ* state mainly deactivates to the S0 state through the direct 1ππ* → S0 IC or mediated by the 1nπ* state. The former nearly barrierless IC channel of 1ππ* → S0 occurs ultrafast via the nearby low-lying 1ππ*/S0 conical intersection. In the latter IC channel of 1ππ* → 1nπ* → S0, the initially photoexcited 1ππ* state first approaches the nearby S2/S1 conical section 1ππ*/1nπ* and then undergoes efficient IC to the 1nπ* state, followed by the further IC to the initial S0 state via the S1/S0 conical intersection 1nπ*/S0. The 1nπ*/S0 conical intersection is estimated to be located 6.0 and 4.9 kcal mol-1 above the 1nπ* state minimum in 5ACyd and 5AdCyd, respectively, at the QM(CASPT2)/MM level. In addition to the efficient singlet-mediated IC channels, the minor ISC routes would populate 1ππ* to T1(ππ*) through 1ππ* → T1 or 1ππ* → 1nπ* → T1. Relatively, the 1ππ* → 1nπ* → T1 route benefits from the spin-orbit coupling (SOC) of 1nπ*/3ππ* of 8.7 cm-1 in 5ACyd and 10.2 cm-1 in 5AdCyd, respectively. Subsequently, the T1 system will approach the nearby T1/S0 crossing point 3ππ*/S0 driving it back to the S0 state. Given the 3ππ*/S0 crossing point located above the T1 minimum and the small T1/S0 SOC, i.e., 8.4 kcal mol-1 and 2.1 cm-1 in 5ACyd and 6.8 kcal mol-1 and 1.9 cm-1 in 5AdCyd, respectively, the slow T1 → S0 would trap the system in the T1 state for a while. The present work could contribute to understanding the mechanistic photophysics and photochemistry of similar aza-nucleosides and their derivatives.

Past and future decline of tropical pelagic biodiversity.

A major research question concerning global pelagic biodiversity remains unanswered: when did the apparent tropical biodiversity depression (i.e., bimodality of latitudinal diversity gradient [LDG]) begin? The bimodal LDG may be a consequence of recent ocean warming or of deep-time evolutionary speciation and extinction processes. Using rich fossil datasets of planktonic foraminifers, we show here that a unimodal (or only weakly bimodal) diversity gradient, with a plateau in the tropics, occurred during the last ice age and has since then developed into a bimodal gradient through species distribution shifts driven by postglacial ocean warming. The bimodal LDG likely emerged before the Anthropocene and industrialization, and perhaps ∼15,000 y ago, indicating a strong environmental control of tropical diversity even before the start of anthropogenic warming. However, our model projections suggest that future anthropogenic warming further diminishes tropical pelagic diversity to a level not seen in millions of years.

MicroRNA-mediated high expression of PDIA3 was correlated with poor prognosis of patients with LUAD.

Lung cancer, especially lung adenocarcinoma (LUAD) as the most common subtype has threatened the health of people. Even though more and more patients diagnosed as LUAD could be treated efficiently or even cured, a spilt of patients still suffer from disease. Here, on the basis of previous research, we firstly performed the mRNA expression of PDIA3 in pan-cancer, and differential expression between tumor and normal groups was followed. We further analyzed the survival difference and ultimately the expression of PDIA3 in LUAD was selected as our current study. Next, we investigated the mRNA and protein expression of PDIA3 from online databases and performed qRT-PCR and western blotting to verify the outcomes. We still analyzed the correlation between the expression of PDIA3 and clinicopathologic parameters and predicted the potential signal pathways as well as the possible upstream molecular of PDIA3. Considering the correlation of PDIA3 and immune infiltration, related analysis of PDIA3 and immune biomarkers along with PD-1/PD-L1, CTLA-4 were made. We clarified the expression of PDIA3 was upregulated in LUAD and its oncogenic role may be played through tumor infiltration. Thus targeting PDIA3 and immune checkpoint could enhance the efficacy of immunotherapy on patients with LUAD.

High bicarbonate concentration increases glucose-induced insulin secretion in pancreatic ß-cells.

Low serum bicarbonate is closely related to type 2 diabetes mellitus. However, the precise role of bicarbonate on glucose homeostasis and insulin secretion remains unknown. In this study, we investigated the effects of bicarbonate concentration on pancreatic ß-cells. It was observed that the high bicarbonate concentration of the cell culture medium significantly increased the glucose-induced insulin secretion (GSIS) levels in mouse islets, MIN6, and the INS-1E ß cells. MIN6 cells presented an impaired GSIS; the cells produced a lower bicarbonate concentration when co-cultured with Capan-1 than when with CFPAC-1. NBCe1, a major bicarbonate transporter was observed to block the increasing insulin secretions, which were promoted by a high concentration of bicarbonate. In addition, higher extracellular bicarbonate concentration significantly increased the intracellular cAMP level, pHi, and calcium concentration with a 16.7 mM of glucose stimulation. Further study demonstrated that a low concentration of extracellular bicarbonate significantly impaired the functioning of pancreatic ß cells by reducing coupling Ca2+ influx, whose process may be modulated by NBCe1. Taken together, our results conclude that bicarbonate may serve as a novel target in diabetes prevention-related research.

Ecological and hydroclimate responses to strengthening of the Hadley circulation in South America during the Late Miocene cooling.

Near-modern ecosystems were established as a result of rapid ecological adaptation and climate change in the Late Miocene. On land, Late Miocene aridification spread in tandem with expansion of open habitats including C4 grassland ecosystems. Proxy records for the central Andes spanning the Late Miocene cooling (LMC) show the reorganization of subtropical ecosystems and hydroclimate in South America between 15 and 35°S. Continental pedogenic carbonates preserved in Neogene basins record a general increase of δ18O and δ13C values from pre-LMC to post-LMC, most robustly occurring in the subtropics (25 to 30°S), suggesting aridification and a shift toward a more C4-plant-dominated ecosystem. These changes are closely tied to the enhancement of the Hadley circulation and moisture divergence away from the subtropics toward the Intertropical Convergence Zone as revealed by climate model simulations with prescribed sea-surface temperatures (SSTs) reflecting different magnitudes of LMC steepening of equator-to-pole temperature gradient and CO2 decline.

Financial toxicity and its associated patient and cancer factors among women with breast cancer: a single-center analysis of low-middle income region in China.

PURPOSE: To assess the financial toxicity (FT) and to investigate patients and cancer characteristic that associated with it in patients admitted in a tertiary hospital in central China. METHODS: This was a cross-sectional study of 166 patients from 188 with stage 0-III women breast cancer admitted in Bethune hospital in Taiyuan, Shanxi province during January-May 2019. FT was self-reported using of financial Toxicity Comprehensive Rating Scale (COST-FACIT). Patients' sociodemographic factors, clinical examination, and cancer treatment were collected from questionnaire and hospital record. The financial concern and coping strategy was self-reported. Factors associated with FT were identified using linear regression analysis. RESULTS: Of the 166 completed the survey, the COST score ranged 0-40 with a mean of 21.2 (median 22.5, standard deviation 8.1). On multivariate linear regression analysis, older age (ß coefficient: 0.20, 95% CI 0.11-0.29, p < 0.001), higher household income (ß coefficient: 3000-5000 Yuan: 7.88, 95% CI 4.74-11.01, p < 0.001; ≥ 5000 Yuan: 12.81, 95% CI 9.54-16.08, p < 0.001) were positively associated with COST scores. Advanced cancer stage was the strongest predictor of FT among the cancer characteristics (ß coefficient: - 4.52, 95% CI - 7.13-1.92, p = 0.001). To cope with the FT, 131 (78.8%) patients decreased non-medical expenses, and 56 (33.7%) reduced or quitted treatment. CONCLUSIONS: FT was significantly associated with patient's age, income, and cancer stage. Women having financial concerns after diagnosis were more likely to reduce their non-medical expenses and even quit treatments. Clinicians should take into account the FT levels in all patients and work out appropriate treatment strategies for optimal clinical outcome.

Adherence to post-surgery follow-up assessment and its association with sociodemographic and disease characteristics in patients with breast cancer in Central China.

BACKGROUND: Follow-up after curative surgery is increasingly recognized as an important component of breast cancer care. Although current guideline regulates the follow-ups, there are no relevant studies on the adherence to it in China. This study investigated the post-surgery follow-up and explored its association with patients, tumor and treatment characteristics. METHODS: A total of 711 patients underwent surgical treatment in Shanxi Bethune Hospital from March 2012 to May 2018 were included in this study. Baseline sociodemographic, tumor, and treatment characteristics were obtained from the hospital electronic medical records. The post-surgery follow-up was reviewed and assessed from the patient's follow-up examination record. Factors associated with the first three-year follow up was evaluated using logistic regression analysis. RESULTS: The annual follow-up rate after surgery decreased gradually from 67.1% at the 1st year, 60.2% at the 3rd year to 51.9% at the 4th year, and 43.5% at the 5th year. Loss of follow-up during the first 3 years after surgery was significantly associated with older age (> 65 years), lower medical insurance coverage, axillary lymph node dissection, and less intensity of systemic treatment. CONCLUSION: A significant downtrend of annual follow-up rate for breast cancer survivors was confirmed in this study. Loss of follow-up within the first 3 years after surgery was associated with both patient's characteristics and treatment. These results will provide evidence to help clinicians to develop tailored patient management after curative surgery.

Effect of KCNH6 on Hepatic Endoplasmic Reticulum Stress and Glucose Metabolism.

Adult patients with a dysfunctional ether-a-go-go 2 (hERG2) protein, which is encoded by the KCNH6 gene, present with hyperinsulinemia and hyperglycemia. However, the mechanism of KCNH6 in glucose metabolism disorders has not been clearly defined. It has been proposed that sustained endoplasmic reticulum (ER) stress is closely concerned with hepatic insulin resistance and inflammation. Here, we demonstrate that Kcnh6 knockout (KO) mice had impaired glucose tolerance and increased levels of hepatic apoptosis, in addition to displaying an increased insulin resistance that was mediated by high ER stress levels. By contrast, overexpression of KCNH6 in primary hepatocytes led to a decrease in ER stress and apoptosis induced by thapsigargin. Similarly, induction of Kcnh6 by tail vein injection into KO mice improved glucose tolerance by reducing ER stress and apoptosis. Furthermore, we show that KCNH6 alleviated hepatic ER stress, apoptosis, and inflammation via the NFκB-IκB kinase (IKK) pathway both in vitro and in vivo. In summary, our study provides new insights into the causes of ER stress and subsequent induction of primary hepatocytes apoptosis.

Design, Synthesis, Molecular Docking Analysis, and Carbonic Anhydrase IX Inhibitory Evaluations of Novel N-Substituted-ß-d-Glucosamine Derivatives that Incorporate Benzenesulfonamides.

A series of novel N-substituted-ß-d-glucosamine derivatives that incorporate benzenesulfonamides were designed using a fragment-based drug design strategy. Each derivative was synthesized and evaluated in vitro for its inhibitory activity against human carbonic anhydrase (hCA) IX; several derivatives displayed desirable potency profiles against this enzyme. The molecular docking studies provided the design rationale and predicted potential binding modes for carbonic anhydrase (CA) IX and three target compounds, including the most potent inhibitor, compound 7f (IC50 = 10.01 nM). Moreover, the calculated Log P (cLog P) values showed that all the compounds tended to be hydrophilic. In addition, topological polar surface area (TPSA) value-based predictions highlighted the selectivity of these carbohydrate-based inhibitors for membrane-associated CA IX.

Effects of Notch2 and Notch3 on Cell Proliferation and Apoptosis of Trophoblast Cell Lines.

AIMS: To investigate the effect of Notch2 and Notch3 on cell proliferation and apoptosis of two trophoblast cell lines, BeWo and JAR. METHODS: Notch2 and Notch3 expression in BeWo and JAR cells was upregulated or downregulated using lentivirus-mediated overexpression or RNA interference. The effect of Notch2 and Notch3 on cell proliferation was assessed by the CCK-8 assay. The effect of Notch2 and Notch3 on the apoptosis of BeWo and JAR cells was evaluated by flow cytometry using the Annexin V-PE Apoptosis kit. Lentivirus-based overexpression vectors were constructed by cloning the full-length coding sequences of human Notch2 and Notch3 C-terminally tagged with GFP or GFP alone (control) into a lentivirus-based expression vector. Lentivirus-based gene silencing vectors were prepared by cloning small interfering sequences targeting human Notch2 and Notch3 and scrambled control RNA sequence into a lentivirus-based gene knockdown vector. The effect of Notch2 and Notch3 on cell proliferation was assessed by the CCK-8 assay. And the effect of Notch2 and Notch3 on the apoptosis of BeWo and JAR cells was evaluated by flow cytometry using the Annexin V PE Apoptosis kit. RESULTS: We found that the downregulation of Notch2 and Notch3 gene expression in BeWo and JAR cells resulted in an increase in cell proliferation, while upregulation of Notch3 and Notch2 expression led to a decrease in cell proliferation. Moreover, the overexpression of Notch3 and Notch2 in BeWo and JAR cells reduced apoptosis in these trophoblast cell lines, whereas apoptosis was increased in the cells in which the expression of Notch3 and Notch2 was downregulated. CONCLUSIONS: Notch2 and Notch3 inhibited both cell proliferation and cell apoptosis in BeWo and JAR trophoblast cell lines.

Reorientation of the "free OH" group in the top-most layer of air/water interface of sodium fluoride aqueous solution probed with sum-frequency generation vibrational spectroscopy.

Many experimental and theoretical studies have established the specific anion, as well as cation, effects on the hydrogen-bond structures at the air/water interface of electrolyte solutions. However, the ion effects on the top-most layer of the air/water interface, which is signified by the non-hydrogen-bonded so-called "free OH" group, have not been explicitly discussed or studied. In this report, we present the measurement of changes of the orientational angle of the "free OH" group at the air/water interface of the sodium fluoride (NaF) solutions at different concentrations using the interface selective sum-frequency generation vibrational spectroscopy (SFG-VS) in the ssp and ppp polarizations. The polarization dependent SFG-VS results show that the average tilt angle of the "free OH" changes from about 36.6° ± 0.5° to 44.1° ± 0.6° as the NaF concentration increases from 0 to 0.94 M (nearly saturated). Such tilt angle change is around the axis of the other O-H group of the same water molecule at the top-most layer at the air/water interface that is hydrogen-bonded to the water molecules below the top-most layer. These results provide quantitative molecular details of the ion effects of the NaF salt on the structure of the water molecules at the top-most layer of the air/water interface, even though both the Na(+) cation and the F(-) anion are believed to be among the most excluded ions from the air/water interface.

Does the community service environment affect the willingness of older adults people to socialize for older adults care?

Population ageing is a significant trend in social development and will remain a fundamental national condition in China for the foreseeable future. Socialized older adults care has become a crucial strategy for China to address population ageing. However, the current levels of acceptance and willingness to seek socialized older adults care among older adults are relatively low. This study focuses on examining how the community environment and services influence older adults people's willingness to engage in social activities related to older adults care. Using data from the China Longitudinal Ageing Social Survey (CLASS) (N = 9,657), this study investigated the impact of the community service environment on older adults people's willingness to participate in social activities related to older adults care through a logit model. The study revealed that 9.15% of older adults (N = 9,657) in China are willing to engage in social activities related to older adults care. Furthermore, the individual characteristics and family support of older adults play a significant role in shaping their willingness to engage in older adults care. The provision of medical services, daily care services, and entertainment venues by the community positively influence older adults people's willingness to participate in social activities related to older adults care (p < 0.01), whereas psychological counselling services have a negative impact (p < 0.01). The impact of community services on older adults people's willingness to engage in social activities related to older adults care varies due to factors such as smoking and chronic diseases. These findings provide valuable insights for improving older adults' social engagement in China.

Triple-Bond Vibrations: Emerging Applications in Energy and Biological Sciences.

Triple bonds, such as that formed between two carbon atoms (i.e., C≡C) or that formed between one carbon atom and one nitrogen atom (i.e., C≡N), afford unique chemical bonding and hence vibrational characteristics. As such, they are not only frequently used to construct molecules with tailored chemical and/or physical properties but also employed as vibrational probes to provide site-specific chemical and/or physical information at the molecular level. Herein, we offer our perspective on the emerging applications of various triple-bond vibrations in energy and biological sciences with a focus on C≡C and C≡N triple bonds.