InSAR and machine learning reveal new understanding of coastal subsidence risk in the Yellow River Delta, China.

Coastal subsidence is a geological disaster that has devastating consequences. However, an accurate understanding of its risks involves more than simply assessing the amount or rate of land subsidence. The existing methods used to evaluate geological disaster risks depend on extensive data collection, entail substantial workloads, suffer from error estimation challenges, and lack regional adaptability. These limitations prevent us from fully understanding coastal subsidence risks in estuarine deltas. Therefore, in this study, we propose a new subsidence risk assessment method that addresses the challenges of traditional geological risk assessments in terms of spatial coverage, spatiotemporal resolution, and data collection difficulty. First, Sentinel-1 multitemporal interferometric synthetic aperture radar (MT-InSAR) and cluster analysis were used to estimate the subsidence hazards. Subsequently, Landsat-8 imagery and a random forest (RF) classifier were used to obtain land use and land cover (LULC), and the analytic hierarchy process (AHP) was used to obtain settlement vulnerability. Thereafter, subsidence susceptibility was derived from the sediment layer thickness. By combining subsidence hazard, vulnerability, and susceptibility, the first subsidence risk map with a 30 m resolution was generated. The results showed that 4.54 % of the Yellow River Delta (YRD) area was high-risk, 8.75 % was medium-risk, and 10.14 % was low-risk. Notably, the risk map shows a clear overlap between high-risk and saltwater mining areas in the YRD. The proposed method is expected to improve our understanding of the coastal subsidence risk in estuarine deltas. Considering that the risk in high-value economic areas in the YRD is increasing, whereas the risk in low-value economic areas may change owing to human activity, early preventive measures are required.

Terahertz spectroscopic detection of amino acid molecules under magnetic field.

Terahertz (THz) waves can cover the characteristic spectra of substances such as plasma, organisms, and biomolecules, whereas THz photons have low energy and do not damage biological tissues. Therefore, its absorption characteristics in the THz region can be used to characterize the internal structure of biomolecules. In this study, we designed a microfluidic chip and combined it with THz technology. The spectral intensity in descending order was found to be deionized water, phenylalanine, histidine, glycine and glutamic acid by observing the THz wave transmission in the range of 0.1-1.0 THz, comparing the frequency domain spectra of four amino acid solutions with volume fraction of 2% and deionized water. It is inferred that different molecular structures of amino acids resulted in different numbers of hydrogen bonds formed between them and water molecules, leading to different degrees of absorption of THz waves. In addition, magnetic fields parallel to the THz wave transmission were used to study the variation of different amino acids with magnetic field intensity. It is found that increasing the magnetic field strength decrease the transmission of THz waves. This is because under the action of the magnetic field, on the one hand, the hydrogen bonds formed by water molecules are strengthened and the absorption of THz waves is enhanced; on the other hand, amino acid molecules aggregate and the radius of molecular clusters increases, thus blocking the transmission of THz waves. Finally, we also calculated the electric conductivity of the solutions to prove the accuracy of the experimental results from a theoretical point of view.

Terahertz spectral properties of glucose and two disaccharides in solid and liquid states.

The vibrational and rotational frequencies of most biological macromolecules fall within the terahertz (THz) band; therefore, the THz wave has a strong ability to distinguish substances. Saccharides are important organic substances and the main source of life-sustaining activities. In this study, the spectral characteristics of D-glucose, α-lactose hydrate, and ß-maltose hydrate were measured in the solid state through THz time-domain spectroscopy in the frequency range of 0.1-2.5 THz. The crystal configurations of these three saccharides were then simulated using solid-state density functional theory, and the experimental results were found to be in good agreement with the simulation results. Furthermore, the spectral characteristics of the three saccharides in solutions were measured. Each saccharide was found to have unique spectral characteristics, and a correlation existed between the THz absorption spectra of the same substance in the solid state and aqueous solution.

Chronic bronchitis is associated with severe exacerbation and prolonged recovery period in Chinese patients with COPD: a multicenter cross-sectional study.

BACKGROUND: Chronic bronchitis (CB) is closely associated with the frequency and severity of chronic obstructive pulmonary disease (COPD) exacerbation. However, little is known about the impact of CB on COPD exacerbations, severe and non-severe, and on recovery from an exacerbation. METHODS: We conducted a nation-wide multicenter cross-sectional survey in China between September 2007 and December 2008. Eleven hospitals participated in this study. Patients' demographic information, presence of CB, overall numbers of COPD exacerbation and severe exacerbation leading to emergency visit, hospitalization and intensive care unit (ICU) stay in the past year, recovery period following the last exacerbation, and well- or poor-recovery were recorded. RESULTS: A total of 1,101 patients with COPD were enrolled and 890 (80.8%) had CB. Patients with CB reported more history of frequent exacerbations (≥2/patient/year) (59.6% vs. 50.7%, P=0.019) and severe exacerbation (% emergency visit ≥1: 28.0% vs. 16.6%, P=0.001; % hospitalization ≥1: 51.2% vs. 28.0%, P<0.001; %ICU stay ≥1: 6.5% vs. 1.9%, P=0.009). Recovery period following the last exacerbation was longer in patients with CB (19.0±16.2 vs. 15.2±14.7 days, P=0.003) and more patients with CB reported poor recovery (85.8% vs. 78.4%, P=0.003). Multivariate analyses showed that CB was independently associated with severe exacerbation requiring emergency visit (adjusted OR, 1.512, P=0.048) and hospitalization (adjusted OR, 2.031, P<0.001) and prolonged recovery period (adjusted regression coefficient 2.861, P=0.030). CONCLUSIONS: CB is associated with frequent exacerbations of COPD in Chinese population, especially severe exacerbations requiring emergency visit and hospitalization admission. Additionally, CB significantly prolongs recovery period following COPD exacerbation.

[Present status of medical treatment for patients with chronic obstructive pulmonary disease based upon different severity classifications].

OBJECTIVE: To survey the present status of medical treatment for Chinese outpatients with chronic obstructive pulmonary disease (COPD) based upon the guidelines for diagnosing and treating COPD (2007 Revised Edition and 2013 Revised Edition) and explore the impact of new guideline on treatment regimens. METHODS: A retrospective study was conducted at 11 participating hospitals. Stable COPD patients were consecutively recruited from outpatient clinics in China between September 2007 and December 2008 and categorized into the Global Initiative for Chronic Obstructive Lung Disease (GOLD) I-IV classification and A-D groups according to the Chinese guidelines for diagnosing and treating COPD (2007 Revised Edition and 2013 Revised Edition). The authors compared the present status of medical treatment of two guidelines and analyze the impact of new guideline on treatment regimens. RESULTS: Among a total of 749 patients, 79.2% (593/749) patients received medical treatment. The distribution of classification GOLD I-IV was 34 (4.5%), 211 (28.2%), 309 (41.3%) and 195 (26.0%). According to the guideline 2007, the patients on medical under-treatment based upon the guidelines in GOLD I-IV classification were 32.4% (11/34), 53.6% (113/211), 57.6% (178/309) and 55.4% (108/195); those on medical treatment: 23.5% (8/34), 3.8% (8/211), 28.8% (89/309) and 33.3% (65/195); those on medical over-treatment: 44.1% (15/34), 42.7% (90/211), 13.6% (42/309), 11.3% (22/195). The distribution of categories A-D was 93 (12.4%), 45 (6.0%), 196 (26.2%), and 415 (55.4%). According to guideline 2013, the patients on medical under-treatment were 34.4% (32/93), 62.2% (28/45), 67.9% (133/196) and 60.7% (252/415); those on medical treatment: 24.7% (23/93), 4.4% (2/45), 32.1% (63 /196) and 39.3% (163/415); those on medical over-treatment: 40.9% (38/93), 33.3% (15/45), 0 and 0. The concordance analysis comparing the judgments of treatment regimens by these two guideline yielded a weighted Kappa coefficient of 0.534 (P < 0.001), indicating that there was a moderate degree of judgments between two guidelines. Medical treatment regimens recommended by new guideline was different from old guideline in 143 COPD patients. Among them, 24 patients (16.8%) required a step-down therapy while 119 patients (83.2%) a step-up therapy. CONCLUSIONS: There are more outpatients with COPD on medical treatment, but few of them have received standardized treatment. Compared with the old GOLD classification, more patients are recommended for a step-up therapy by new stratification.

A Filifactor alocis-centered co-occurrence group associates with periodontitis across different oral habitats.

Periodontitis is a highly prevalent polymicrobial disease worldwide, yet the synergistic pattern of the multiple oral pathogens involved is still poorly characterized. Here, saliva, supragingival and subgingival plaque samples from periodontitis patients and periodontally healthy volunteers were collected and profiled with 16S rRNA gene pyrosequencing. Different oral habitats harbored significantly different microbiota, and segregation of microbiota composition between periodontitis and health was observed as well. Two-step redundancy analysis identified twenty-one OTUs, including Porphyromonas gingivalis, Tannerella forsythia and Filifactor alocis, as potential pathogens that were significantly associated with periodontitis and with two periodontitis diagnostic parameters (pocket depth and attachment loss) in both saliva and supragingival plaque habitats. Interestingly, pairwise correlation analysis among the 21 OTUs revealed that Filifactor alocis was positively correlated with seven other putative pathogens (R > 0.6, P < 0.05), forming a co-occurrence group that was remarkably enriched in all three habitats of periodontitis patients. This bacterial cluster showed a higher diagnostic value for periodontitis than did any individual potential pathogens, especially in saliva. Thus, our study identified a potential synergistic ecological pattern involving eight co-infecting pathogens across various oral habitats, providing a new framework for understanding the etiology of periodontitis and developing new diagnoses and therapies.

A phylo-functional core of gut microbiota in healthy young Chinese cohorts across lifestyles, geography and ethnicities.

Structural profiling of healthy human gut microbiota across heterogeneous populations is necessary for benchmarking and characterizing the potential ecosystem services provided by particular gut symbionts for maintaining the health of their hosts. Here we performed a large structural survey of fecal microbiota in 314 healthy young adults, covering 20 rural and urban cohorts from 7 ethnic groups living in 9 provinces throughout China. Canonical analysis of unweighted UniFrac principal coordinates clustered the subjects mainly by their ethnicities/geography and less so by lifestyles. Nine predominant genera, all of which are known to contain short-chain fatty acid producers, co-occurred in all individuals and collectively represented nearly half of the total sequences. Interestingly, species-level compositional profiles within these nine genera still discriminated the subjects according to their ethnicities/geography and lifestyles. Therefore, a phylogenetically diverse core of gut microbiota at the genus level may be commonly shared by distinctive healthy populations as functionally indispensable ecosystem service providers for the hosts.

IL-22 deficiency alters colonic microbiota to be transmissible and colitogenic.

IL-22 is a good candidate to play a critical role in regulating gut microbiota because it is an important inducer of antimicrobial peptides and mucins in the gut. However, whether IL-22 participates in immune homeostasis by way of modulating gut microbiota remains to be elucidated. In this study, we find, through 16S rRNA gene-pyrosequencing analysis, that healthy IL-22-deficient mice had altered colonic microbiota, notably with decreased abundance of some genera, including Lactobacillus, and increased levels of others. Mice harboring this altered microbiota exhibited more severe disease during experimentally induced colitis. Interestingly, this altered gut microbiota can be transmitted to cohoused wild-type animals along with the increased susceptibility to this colitis, indicating an important role for IL-22 in shaping the homeostatic balance between immunity and colonic microbiota for host health.

[Attitudes and actions of chronic obstructive pulmonary disease patients on treatment:a national multi-center investigative study].

OBJECTIVE: To investigate the attitudes and actions of patients with chronic obstructive pulmonary disease (COPD) on treatment. METHODS: A nation-wide multi-center, questionnaire study was carried out to investigate the patient understanding and experience of COPD treatment between Sep. 2007 and Dec. 2008. The questionnaire included the patients' understanding of goal of COPD treatment, previous treatment, and expectation on drugs. The data were analyzed by descriptive statistical methods. RESULTS: 2072 patients with COPD in 11 centers were interviewed in the study. The final effective questionnaires were collected from 1698 cases. 653 patients had known of COPD. The attitudes and actions on treatment were analyzed based on these patients. The patients had different understanding of goals for COPD treatment, including 59.1% (384/650) for relieving symptoms. In recent 3 months, the most commonly used drugs were theophylline (53.7%, 351/653), iprotropium (39.8%, 260/653), tiotropium (27.1%, 177/653). 72.0% (465/646) patients used the drugs according to the prescriptions. There were more than 80% patients who did not understand the side effects of anti-cholinergics, ß-adrenergic agonists, inhaled steroids, inhaled steroid/long-acting ß-agonist combination therapy, or theophyllines. 37.4% (240/641) patients were afraid of side effects of inhaled steroids. 42.2% (274/650) patients often took antibiotics. There was no oxygen supply at home in 60.1% (391/651) patients. 70.5% (457/648) did not have pulmonary rehabilitation. Requirement of long-term regular treatment was considered in 77.4% (500/646) patients. The most important thing about patients' attitude on ideal drugs for COPD was drug efficacy (79.6%, 481/604). The most ideal drug used in the past was fluticasone/salmeterol or tiotropium (16.9%, 78/461). CONCLUSIONS: Patients had different attitudes and actions on COPD treatment. Patient education should be strengthened to realize treatment goals for COPD.

[Study on drug-resistance of Mycobacterium tuberculosis isolated from coal workers with silico-tuberculosis].

OBJECTIVE: To study the gene mutation and streptomycin, isoniazid or rifampicin resistance of Mycobacterium isolated from silico-tuberculosis patient's sputum so as to find a more effective therapy for this disease. METHODS: Mycobacteria tuberculosis were separated from 96 coal worker with silico-tuberculosis firstly. Then rpsL, KatG and rpoB fragments of genome were copied with PCR and compared their SSCP profiles with standard strains. RESULTS: 67 strains of streptomycin, isoniazid or rifampicin resistant Mycobacteria tuberculosis were found in routine drug resistance test, with the percentages of 80.5% (54/67), 58.2% (39/67) respectively. PCR-SSCP showed that out of 67 drug-resistant strains, 66(98.5%) of rpsL, 47(70.1%) of rpoB and 42(62.7%) of KatG appeared abnormal. CONCLUSION: Most of the resistant strains appeared gene mutation. The mution rates were higher than the results from routine drug resistance test.