•A simple program was developed for fast tilting crystals to zone axes.•The program provides two options, tilting a crystal from one zone axis to another and tilting when the orientation is slightly ...off the zone axis.•Electron-beam sensitive materials including zeolites and MOFs have been tested to prove the feasibility of this new approach.•The calculated angles by the program show good match with the actual experimental ones with an error of ±0.6°.
Tilting crystals to proper zone axes is a necessary but tedious work in taking selected area electron diffraction patterns (SAED) and high-resolution images using transmission electron microscope (TEM). This process not only costs a lot of time but also limits the application of TEM in electron-beam sensitive materials. Therefore, it is desirable to develop a simple method for tilting crystals from random orientations to a specific zone axis quickly. Herein, we describe a novel program, Zones, which can index the electron diffraction pattern and calculate the tilting angles of a double-tilt sample holder from the current orientation to a desired zone axis. It can also bring crystals that are slightly deviated from a zone axis to the exact zone with the help of Laue ring in the diffraction pattern. This program has been successfully applied to studies of zeolites and metal-organic frameworks (MOFs), known as being electron-beam sensitive. The program shows its power not only in saving the operator's time but also in preventing the crystals from quick beam damages.
The start-up and operational performance (total 212 days, including the start-up of 164 days) of an anaerobic baffled reactor (ABR), which is used to treat heavy oil produced water, was studied ...without the temperature control. Inoculums were mixtures of acclimated sediment taken from a heavy oil produced water treatment plant and digested sludge from a sewage wastewater treatment plant. The rod-shaped and spherical granules with colors of henna and black, in which
Clostridia,
Methanosarcina and Methanothrx sp. were main populations, were observed in each compartment of ABR after the reactor’s successful start-up (day 164).
Rhodopseudomonas with the activity of lipase and halotolerant, as a kind of photosynthetic bacteria, was also observed in the first five compartments. X-ray diffraction (XRD) showed that the spherical granule sludge was compact and contained a large amount of organics, amorphous materials, and crystals of Fe
2O
3, FeS, and CaCO
3, whereas the rod-shaped granule sludge was incompact without crystals of Fe
2O
3, FeS, and CaCO
3. Scanning electron microscope (SEM) showed that the skeleton construction of this rod-shaped granule was filamentous bacteria and amount of extracellular polymeric substances (EPS). The ABR, after successful start up, can achieve high average chemical oxygen demand (COD) and oil removals of 65% and 88% for heavy oil produced water with poor nutrient (COD:TN:TP, 1200:15:1) and high salt concentration (1.15–1.46%), respectively. Furthermore, ABR kept stable during 2.5 times the COD level shock load (0.50
kg COD
m
−3 d
−1) for four days.
Lactic acid bacteria (LAB) are industrially important bacteria that are widely used in the fermented food industry, especially in the manufacture of yogurt. Characteristic flavors are produced by LAB ...during fermentation and storage that affect the quality and acceptability of fermented milk products. In this study, the volatile compounds in milk fermented by Streptococcus thermophilus IMAU80842 alone, Lactobacillus delbrueckii ssp. bulgaricus IMAU20401 alone, or both species together were identified using solid-phase microextraction methods coupled with gas chromatography-mass spectrometry. A total of 53, 43, and 32 volatile compounds were identified in milk fermented by S. thermophilus alone, L. delbrueckii ssp. bulgaricus alone, or both species together, respectively. The presence of some important flavor compounds was confirmed: acetic acid, acetaldehyde, acetoin, 2,3-butanedione, ethanol, and 1-heptanol. Our results demonstrate that the composition of the volatile compounds in fermented milk depends on the species of LAB used and whether they are used alone or in combination. This is important for the selection of appropriate starter cultures for the production of different types of fermented milk product with particular flavors.
Avermectins are major antiparasitic agents used commercially in animal health, agriculture and human infections. To improve the fermentation efficiency of avermectins, for the first time a plasma jet ...generated by a novel atmospheric pressure glow discharge (APGD) was employed to generate mutations in Streptomyces avermitilis. The APGD plasma jet, driven by a radio frequency (RF) power supply with water-cooled and bare-metallic electrodes, was used as a new mutation method to treat the spores of S. avermitilis. The plasma jet yielded high total (over 30%) and positive (about 21%) mutation rates on S. avermitilis, and a mutated strain, designated as G1-1 with high productivity of avermectin B1a and genetic stability, was obtained. Because of the low jet temperature, the high concentrations of the chemically reactive species and the flexibility of its operation, the RF APGD plasma jet has a strong mutagenic effect on S. avermitilis. This is a proof-of-concept study for the use of an RF APGD plasma jet for inducing mutations in microbes. We have shown that the RF APGD plasma jet could be developed as a promising and convenient mutation tool for the fermentation industry and for use in biotechnology research.
The Pearl River Delta (PRD) region in South China is one of the most economically developed regions in China, but it is also noted for its severe air pollution due to industrial/metropolitan ...emissions. In order to continuously improve the understanding and quantification of air pollution in this region, an intensive campaign was executed in PRD during October–November 2008. Here, we report and analyze Aerodyne High-Resolution Aerosol Mass Spectrometer measurements at Kaiping, a rural site downwind of the highly-polluted central PRD area, to characterize the general features of submicron particulate pollution in the regional air. The mean measured PMsub>1 mass concentration was 33.1±18.1 μg m−3 during the campaign and composed of organic matter (33.8%), sulfate (33.7%), ammonium (14.0%), nitrate (10.7%), black carbon (6.7%), and chloride (1.1%), which is characterized by high fractions of inorganic ions due to huge emissions of SO2 and NOx in PRD. The average size distributions of the species (except BC) were all dominated by an accumulation mode peaking at ~450 nm in vacuum aerodynamic diameter. Calculations based on high-resolution organic mass spectra indicate that C, H, O, and N on average contributed 56.6, 7.0, 35.1, and 1.3% to the total organic mass, respectively, corresponding to an organic matter mass to organic carbon mass ratio (OM/OC) of 1.77±0.08. Based on the high-resolution organic mass spectral dataset observed, Positive Matrix Factorization (PMF) analysis differentiated the organic aerosol into three components, i.e., biomass burning (BBOA) and two oxygenated (LV-OOA and SV-OOA) organic aerosols, which on average accounted for 24.5, 39.6 and 35.8% of the total organic mass, respectively. The BBOA showed strong features of biomass burning emissions and has been mainly attributed to the open field burning of crop residues after the harvest in PRD rural areas. The LV-OOA and SV-OOA were found to correspond to more aged (and thus less-volatile) and fresher (and semi-volatile) secondary organic aerosol (SOA), respectively. Analysis of meteorological influence supported that regional transport from the central PRD area was the major origin of the PM1 observed at the Kaiping site.
Summary
Arrhythmia, pneumonia, cardiac insufficiency, a high leukocyte count, and low albumin concentrations were associated with increased 30-day mortality in elderly hip fracture patients after ...surgery. It is important to improve short-term survival rates by optimizing the respiratory and cardiac function of geriatric patients before they undergo surgery.
Introduction
This study aims to investigate the 30-day mortality and related risk factors for elderly patients following surgery for hip fractures.
Methods
This retrospective study examined chart reviews for evaluating associations of gender, age, fracture site, biochemical indicators, pre-surgery comorbidities, number of pre-surgery comorbidities, time to surgery and anesthesia and surgery methods with postoperative 30-day mortality in elderly hip fracture surgery patients.
Results
A total of 1,004 patients were included in the study and 43 (4.3%) patients died within 30 days after surgery. Univariate analysis showed that patients in the non-survival group had a higher mean age, higher leukocyte counts, lower hemoglobin and albumin levels, a higher proportion of arrhythmias, pneumoniae and cardiac insufficiency and number of presurgical comorbidities than the survival group (all
P
-values < 0.05). Multivariate logistic analysis further confirmed that arrhythmia (OR = 2.033,
P
= 0.038), pneumonia (OR = 2.246,
P
= 0.041), cardiac insufficiency (OR = 2.833,
P
= 0.029), high leukocyte count (OR = 1.139,
P
= 0.009), and low albumin (OR = 0.925,
P
= 0.041) were all significant risk factors for mortality 30 days after surgery.
Conclusions
This study demonstrates that arrhythmia, pneumonia, cardiac insufficiency, a high leukocyte count, and low albumin concentrations were associated with increased 30-day mortality in elderly hip fracture patients after surgery.
Based on the flipped‐classroom model and the potential motivational and instructional benefits of digital games, we describe a flipped game‐based learning (FGBL) strategy focused on preclass and ...overall learning outcomes. A secondary goal is to determine the effects, if any, of the classroom aspects of the FGBL strategy on learning efficiency. Our experiments involved 2 commercial games featuring physical motion concepts: Ballance (Newton's law of motion) and Angry Birds (mechanical energy conservation). We randomly assigned 87 8th‐grade students to game instruction (digital game before class and lecture‐based instruction in class), FGBL strategy (digital game before class and cooperative learning in the form of group discussion and practice in class), or lecture‐based instruction groups (no gameplay). Results indicate that the digital games exerted a positive effect on preclass learning outcomes and that FGBL‐strategy students achieved better overall learning outcomes than their lecture‐based peers. Our observation of similar overall outcomes between the cooperative learning and lecture‐based groups suggests a need to provide additional teaching materials or technical support when introducing video games to cooperative classroom learning activities.
Lay Description
What is already known about this topic:
Digital game benefits in terms of science learning and learning motivation.
Commercial game cannot be used to directly teaching course content.
Flipped classroom help students to actively construct preclass knowledge.
Students in Flipped classroom may lack motivation to view preclass lectures.
What this paper adds:
An out‐of‐class application of commercial games for physics education is described.
A modified flipped classroom instructional model are proposed.
Design issues for in‐class cooperative learning‐based digital games are discussed.
Implications for practice and/or policy:
The commercial games can be used to promote active preclass learning.
The FGBL strategy could improve preclass learning and overall learning outcomes.
The FGBL strategy is recommended for the learning of specific topics.
Summary
The effects of exogenous pulsed electromagnetic field (PEMF) stimulation on T1DM-associated osteopathy were investigated in alloxan-treated rabbits. We found that PEMF improved bone ...architecture, mechanical properties, and porous titanium (pTi) osseointegration by promoting bone anabolism through a canonical Wnt/β-catenin signaling-associated mechanism, and revealed the clinical potential of PEMF stimulation for the treatment of T1DM-associated bone complications.
Introduction
Type 1 diabetes mellitus (T1DM) is associated with deteriorated bone architecture and impaired osseous healing potential; nonetheless, effective methods for resisting T1DM-associated osteopenia/osteoporosis and promoting bone defect/fracture healing are still lacking. PEMF, as a safe and noninvasive method, have proven to be effective for promoting osteogenesis, whereas the potential effects of PEMF on T1DM osteopathy remain poorly understood.
Methods
We herein investigated the effects of PEMF stimulation on bone architecture, mechanical properties, bone turnover, and its potential molecular mechanisms in alloxan-treated diabetic rabbits. We also developed novel nontoxic Ti2448 pTi implants with closer elastic modulus with natural bone and investigated the impacts of PEMF on pTi osseointegration for T1DM bone-defect repair.
Results
The deteriorations of cancellous and cortical bone architecture and tissue-level mechanical strength were attenuated by 8-week PEMF stimulation. PEMF also promoted osseointegration and stimulated more adequate bone ingrowths into the pore spaces of pTi in T1DM long-bone defects. Moreover, T1DM-associated reduction of bone formation was significantly attenuated by PEMF, whereas PEMF exerted no impacts on bone resorption. We also found PEMF-induced activation of osteoblastogenesis-related Wnt/β-catenin signaling in T1DM skeletons, but PEMF did not alter osteoclastogenesis-associated RANKL/RANK signaling gene expression.
Conclusion
We reveal that PEMF improved bone architecture, mechanical properties, and pTi osseointegration by promoting bone anabolism through a canonical Wnt/β-catenin signaling-associated mechanism. This study enriches our basic knowledge for understanding skeletal sensitivity in response to external electromagnetic signals, and also opens new treatment alternatives for T1DM-associated osteopenia/osteoporosis and osseous defects in an easy and highly efficient manner.
Tooth development and regeneration are regulated through a complex signaling network. Previous studies have focused on the exploration of intracellular signaling regulatory networks, but the ...regulatory roles of extracellular networks have only been revealed recently. Proteoglycans, which are essential components of the extracellular matrix (ECM) and pivotal signaling molecules, are extensively involved in the process of odontogenesis. Proteoglycans are composed of core proteins and covalently attached glycosaminoglycan chains (GAGs). The core proteins exhibit spatiotemporal expression patterns during odontogenesis and are pivotal for dental tissue formation and periodontium development. Knockout of core protein genes Biglycan, Decorin, Perlecan, and Fibromodulin has been shown to result in structural defects in enamel and dentin mineralization. They are also closely involved in the development and homeostasis of periodontium by regulating signaling transduction. As the functional component of proteoglycans, GAGs are negatively charged unbranched polysaccharides that consist of repeating disaccharides with various sulfation groups; they provide binding sites for cytokines and growth factors in regulating various cellular processes. In mice, GAG deficiency in dental epithelium leads to the reinitiation of tooth germ development and the formation of supernumerary incisors. Furthermore, GAGs are critical for the differentiation of dental stem cells. Inhibition of GAGs assembly hinders the differentiation of ameloblasts and odontoblasts. In summary, core proteins and GAGs are expressed distinctly and exert different functions at various stages of odontogenesis. Given their unique contributions in odontogenesis, this review summarizes the roles of proteoglycans and GAGs throughout the process of odontogenesis to provide a comprehensive understanding of tooth development.
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