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The microbial potential of Penicilliumhas received critical attention. The present research aimed to elucidate the efficacy of crude enzyme secreted from Penicillium oxalicumWX-209 in degrading citrus segments and evaluate the safety of the process. Results showed that citrus segment membranes gradually dissolved after treatment with the crude enzyme solution, indicating good degradation capability. No significant differences in body weight, food ingestion rate, hematology, blood biochemistry, and weight changes of different organs were found between the enzyme intake and control groups. Serial experiments showed that the crude enzyme had high biological safety. Moreover, the whole genome of P. oxalicumWX-209 was sequenced by PacBio and Illumina platforms. Twenty-five scaffolds were assembled to generate 36 Mbp size of genome sequence comprising 11 369 predicted genes modeled with a GC content of 48.33 %. A total of 592 genes were annotated to encode enzymes related to carbohydrates, and some degradation enzyme genes were identified in strain P. oxalicumWX-209.

Enzyme promiscuity is evolutionarily advantageous to plants for gaining new enzyme functions when adapting to environmental challenges. However, this promiscuity can negatively affect the expression of genes encoding for plant enzymes in microorganisms. Here, we show that refining the promiscuity of flavonoid 3′-hydroxylase (F3′H) and 4′-O-methyltransferase (F4′OMT) improves (2S)-hesperetin production in Escherichia coli. First, we employed inverse molecular docking to screen a highly substrate-specific ThF3′H from Tricyrtis hirta, which could selectively convert 100 mg L–1(2S)-naringenin to (2S)-eriodictyol but not (2S)-isosakuranetin, with a cytochrome P450 reductase from Arabidopsis thaliana. Second, we employed a directed evolution approach to restrict the promiscuity of MpOMT from Mentha × piperita. The strain harboring the MpOMTS142Vmutant presented a remarkably increased preference for (2S)-eriodictyol. Finally, 27.5 mg L–1(2S)-hesperetin was produced, while only minor amounts of (2S)-eriodictyol and (2S)-isosakuranetin accumulated as byproducts. This value represents a 14-fold increase in (2S)-hesperetin compared to the parental strain, along with a dramatic reduction in side products. Our work highlights the benefit of alleviating the promiscuity of plant enzymes when engineering production of natural products by microbial cell factories.

High-fat diet (HFD) is closely related to the formation of metabolic diseases. Studies have confirmed that neohesperidin dihydrochalcone (NHDC) possesses the biological activity of preventing glycolipid metabolism disorder. To explore the mechanism of its preventive activity against glucolipid metabolism disorder, HFD-treated rats were orally administered with NHDC for 12 weeks continuously. The results showed that, compared with the HFD group, the intervention of 40–80 mg/kg body weight of NHDC effectively downregulated the level of fasting blood glucose. Western blot analysis revealed that the treatment of NHDC alleviated the inhibitory effect of HFD on the expression of hepatic GLUT-4 and IRS-1. Further studies confirmed that NHDC reduced the degree of HFD-stimulated inflammation of ileum through the TLR4/MyD88/NF-κB signaling pathway. Moreover, ileum intestinal flora analysis showed that intragastric administration of NHDC reversed the change of Proteobacteria abundance and the Firmicutes/Bacteroidetes (F/B) ratio caused by HFD. At the generic level, NHDC promoted the relative abundance of Coprococcus, Bifidobacterium, Clostridium, Oscillospira, and [Eubacterium], while reducing the relative abundance of Defluviitaleaand Prevotella. Taken together, these findings suggest that NHDC possesses the biological activity of improving HFD-induced glycolipid metabolism disorder.

Prussian blue (PB) and its analogues (PBAs) are promising coordination polymers (CPs) with an adjustable composition and open framework. Nonetheless, their intrinsic electrochemical activity and electrical conductivity are poor, which hinder their applications in energy conversion and storage. In catalytic applications, metal compounds derived from PB/PBAs have a lot of advantages, such as outstanding stability, selectivity, and electrical conductivity. Furthermore, they can be used as electrode materials for electrochemical energy storage and conversion, while having preferable electronic conductivity, sufficient catalytic active sites, as well as a larger specific surface area and tunable size to achieve an optimized performance. This review summarizes the current achievements of PB/PBA-derived metallic nanomaterials, as well as the existing limitations, urgent challenges and future development.The electrochemical applications of Prussian blue/Prussian blue analogues-derived non-oxidized metallic materials are overviewed. Based on a variety of structures, various materials, including sulfides, phosphates, selenides, etc., are reviewed, and optimization strategies for new energy storage and conversion devices are given. We aim to provide readers with the latest progress on this rapidly developing area.

The controllable synthesis of metal-based nanoclusters for heterogeneous catalytic reactions has received considerable attention. Nevertheless, manufacturing these architectures, while avoiding aggregation and retaining surface activity, remains challenging. Herein, for the first time we designed NiCoFe-Prussian blue analogue (PBA) nanocages as a support for in situ dispersion and anchoring of polymetallic phosphide nanoparticles (pMP-NPs). Benefiting from the porous surfaces and the synergistic effects between pMP-NPs and the cyano groups in PBA, the NiCoFe-P-NP@NiCoFe-PBA nanocages exhibit a significantly enhanced catalytic activity for oxygen evolution reaction (OER) with an overpotential of 223 mV at 10 mA cm–2and a Tafel slope of 78 mV dec–1, outperforming the NiCoFe-PBA nanocubes, NiCoFe-P nanocages, NiFe-P-NP@NiFe-PBA nanocubes, and CoFe-P-NP@CoFe-PBA nanoboxes. This work not only offers the synthesis strategy of in situ anchoring pMP-NPs on PBA nanocages but also provides a new insight into optimized Gibbs free energy of OER by regulating electron transfer from metallic phosphides to PBA substrate.

Obesity is a global pandemic and public health crisis over decades. Except for physical activity, dietary adjustments, pharmacotherapy and surgical interventions, prebiotics, which are believed to relieve obesity by modulating the host gut microbiota, have been a hot research area in recent years. Thus, in this study, our objective was to investigate the effects of Citrus aurantiumL. 'Daidai' physiological premature fruit drop (DDPD) on obesity, and further explore whether the anti-obesity effects of DDPD relies on alterations in gut microbiota. Our findings revealed that supplementation with DDPD effectively alleviated HFD-induced obesity in mice, concomitantly reducing inflammation and oxidative stress. Moreover, DDPD reversed the imbalance of gut microbiota induced by HFD, enhancing beneficial bacteria associated with improved obesity, such as Bifidobacterium, Lachnospiraceae_NK4A136_group, Ruminococcus, and Muribaculaceae. Fecal microbiota transplantation experiments demonstrated that DDPD-induced alterations in microbiota effectively mitigated weight gain and lipid abnormalities induced by HFD, while reshaping the microbiota composition of recipient mice to resemble that of donor mice. Notably, beneficial lipid metabolism bacterium Lachnospiraceae_NK4A136_groupidentified in donor mice successfully colonized in recipient mice. Additionally, transcriptomic analysis indicated that DDPD modulated lipid metabolism through regulating the expression of genes linked to Cpt1a, Agpat1, and Pnpla3. In conclusion, DDPD demonstrated promising anti-obesity properties, offering potential solutions to the global obesity epidemic.

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ajo.2004.11.052 Byline: Jui-Yang Lai (a)(d), Ko-Hua Chen (b)(c)(d), Wen-Ming Hsu (b)(c), Te-Hsiao Lee (e), Shan-Yang Lin (b) Abstract: To report the ultrastructural and elemental features of two opacified intraocular lenses (IOLs). Author Affiliation: (a) Department of Chemical Engineering, National Tsing Hua University, Hsinchu, Taiwan, Republic of China (b) Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China (c) National Yang Ming University, Taipei, Taiwan, Republic of China (d) Division of Medical Engineering, National Health Research Institutes, Taipei, Taiwan, Republic of China (e) Potech Refraction and Cataract Center, Taipei, Taiwan, Republic of China Article History: Accepted 24 November 2004 Article Note: (footnote) Supported in part by Taipei Veterans General Hospital Grant (VGH-92-360-5).

Sequence from BAC clones spanning chicken microchromosome GGA28 is analyzed to facilitate functional and evolutionary analysis of one especially gene-rich, rearrangement-prone genomic region. Results reveal that chromosome rearrangement may not have been random over vertebrate evolution but positioned preferentially within specific fragile regions.

The genome sequence for key motifs is explored and then constructed and manually curated gene models incorporating those sequences in order to define the full repertoire of human KRAB-zinc finger (ZNF) proteins. The results show that KRAB-ZNF genes are widely expressed and clustered genes are typically not coregulated, indicating that paralogs have evolved to fill roles in many different biological processes.

Temperature is the most important factor that affects the metabolism of harvested plants. The aim of this study was to investigate the influence and mechanisms of temperature on the antioxidant system in fresh-cut daylily flowers (Hemerocallis lilioasphodelusL.; used for food consumption) during storage. Daylily flowers were harvested and immediately treated by either chilling at 5 °C for 5 days, or by heating with 50 °C hot air for 5 min, then stored at 20 °C for 5 days. The chilling and heating treatments maintained the organoleptic quality and enhanced the antioxidant system of cut daylily flowers. However, different reactions of the antioxidant system were observed under the different temperature treatments. The chilling treatment dramatically enhanced the activities of superoxide dismutase, ascorbate peroxidase, peroxidase, and phenylalanine ammonia lyase, while it decreased the activity of lipoxygenase. Meanwhile, the heating treatment enhanced catalase activity and decreased polyphenol oxidase activity. In addition, the heating treatment reduced the O2−production rate and H2O2content compared to the control. Changes in membrane permeability, total phenolic content, total flavonoid content, and diphenyl-1-picrylhydrazyl clearance activity showed no significant difference between the chilling and heating treatments, owning to the steady content of phenolic and flavonoid compounds and the delay in the generation of quinones. Thus, our results indicate that cold and heat treatments can impact the preservation of harvested daylilies used for food consumption.

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Diabetes elevates matrix metalloproteinase-9 (MMP-9) in the retina and its capillary cells, and activated MMP-9 damages mitochondria, accelerating retinal capillary cell apoptosis, a phenomenon which precedes the development of retinopathy. Diabetes also favors epigenetic modifications regulating the expression of many genes. DNA methylation is maintained by methylating–hydroxymethylating enzymes, and retinal DNA methyltransferase (Dnmt) is activated in diabetes. Our aim is to investigate the role of DNA methylation in MMP-9 regulation. The effect of high glucose on 5-methylcytosine (5mC) and 5-hydroxymethyl cytosine (5hmC), and binding of Dnmt1 and hydroxymethylating enzyme (Tet2) on MMP-9 promoter were quantified in retinal endothelial cells. Specific role of Tet2 in MMP-9 activation was validated using Tet2-siRNA. The results were confirmed in the retina from streptozotocin-induced diabetic mouse. Although glucose increased Dnmt1 binding at MMP-9 promoter, it decreased 5mC levels. At the same promoter site, Tet2 binding and 5hmC levels were elevated. Tet2-siRNA ameliorated increase in 5hmC and MMP-9 transcription, and protected mitochondrial damage. Diabetic mice also presented similar dynamic DNA methylation changes in the retinal MMP-9 promoter. Thus, in diabetes transcription of retinal MMP-9 is maintained, in part, by an active DNA methylation–hydroxymethylation process, and regulation of this machinery should help maintain mitochondrial homeostasis and inhibit the development/progression of diabetic retinopathy.

Solid-state mechanochemical grinding is important for promoting cocrystal formation, particularly in the design of new solids in the pharmaceutical industry. Pharmaceutical cocrystals are defined as crystalline materials comprising an active pharmaceutical ingredient (API) and one or more appropriate coformers in a definite stoichiometric ratio, formed via non-covalent interactions. Recently, both the US FDA (2013) and the EU EMA (2015) provided a Guidance for Industry and a Reflection Paper, respectively, emphasizing that cocrystals are a new type of substance with potential applications in the pharmaceutical industry. This paper contains a brief and systematic overview of pharmaceutical cocrystals prepared by four grinding processes: neat grinding, solvent-assisted grinding, thermal stress after neat grinding, and polymer-assisted grinding. The paper also highlights some examples of pharmaceutical cocrystals prepared by the above grinding approaches, and discusses the stability of cocrystals prepared by mechanical grinding. Also, an overview of cocrystals that are commercially available or undergoing clinical trials is given. A novel methodology for real-time and in situ monitoring of mechanochemical grinding reactions using various analytical techniques is addressed and can be expected to be applied in the near future.

Ganoderma lucidum(G. lucidum) is one of the well-known mushrooms in China, which has G. lucidum polysaccharides (GLP) that have been widely studied for various biological activities, such as antioxidant, antitumor, antiinflammatory, antiviral, antidiabetes, and immunomodulatory activities. A signal transducer and activator of transcription (STAT) signaling pathway is related to cell proliferation and apoptosis. The relationship between STAT and intestinal protection of GLP is still unknown. We studied the inhibitors AG490 in the STAT pathway and its downstream molecules to analyze the unique effects in the protection of GLP against palmitic acid (PA)-induced porcine intestinal epithelial cells (IPEC-J2) injury. Compared to PA treatment, GLP?+?PA obviously decreased Ca2+concentration, H2O2production, NF-E2-related factor 2 (Nrf2) nuclear translocation, STAT1 and STAT2 protein levels, and increased nuclear factor kappa-B (NF-?B) nuclear translocation and p-STAT3/STAT3 ratio in IPEC-J2 cells. After inhibition of STAT3 signaling, p-STAT3/STAT3 ratio, NF-?B nuclear translocation obviously decreased and Nrf2 nuclear translocation significantly increased in the GLP?+?PA group. The protection of GLP on proliferation and apoptosis of PA-induced IPEC-J2 cells was suppressed by inhibiting STAT3. The STAT3 pathway regulated the enterocyte-protective effects of GLP by modulating the nuclear translocation of Nrf2 and NF-?B. We provide new insights into the mechanism of STAT signaling for the protection of GLP on PA-induced intestinal epithelial cell injury.

The effect of Povacoat on the solid state characteristics and polymorphic transformation of γ-form of indomethacin (γ-IMC) after solvent co-evaporation via two drying methods was investigated by thermoanalytical and FTIR spectroscopic studies. The types of solvents (water, ethanol, and water:ethanol (1:9 ~ 2:8, v/v)), weight ratios of Povacoat:IMC (4:1 ~ 4:10, w/w), and drying methods (air-drying and microwave-drying) were selected as variables in this study. A physical mixture of Povacoat and γ-IMC was also carried out by neat grinding process. The results indicate that there was no interaction between Povacoat and γ-IMC or no polymorphic change of γ-IMC after the neat co-grinding process. Since Povacoat was only soluble in water or <30% ethanol aqueous solution but γ-IMC was only soluble in organic solvents, different solvents and drying methods might significantly influence the solid-state characteristics of IMC formed in the presence of Povacoat. It was found that the amorphous IMC was formed in the Povacoat/IMC evaporates after dissolving both Povacoat and γ-IMC in water:ethanol (mixed ratio=1:9 and 2:8, v/v) and co-evaporation via microwave-drying, whereas the α-IMC was formed in the Povacoat/IMC evaporates via the air-drying method. In addition, the predominate α-IMC formation was only found in all the Povacoat/IMC evaporates with different weight ratios prepared by previously dissolving in water:ethanol (1:9, v/v) and co-evaporation via air-drying, but the amorphous IMC formation after co-evaporation via microwave-drying was obtained except the 4:10 (w/w) weight ratio. The thermal effect of microwave irradiation and the presence of Povacoat might be responsible for the amorphous IMC formation in the Povacoat/IMC evaporates.

An acute sludge was unexpectedly produced in the gallbladder of a woman with acute myocarditis, liver dysfunction and acute cholecystitis. This study aimed to determine whether the morphological features and chemical composition of this acute gallbladder sludge were different from common chronic gallstones. This acute gallbladder sludge and 12 patients' chronic gallstones were analyzed using histopathological examination, SEM, FTIR spectroscopy and X-ray fluorescence analysis. The chronic gallstones from the 12 patients were classified into calcium bilirubinate (CaBR), cholesterol (Chol) and CaBR–Chol mixed stones. The acute gallbladder sludge was not consistent with chronic gallstones but had developed within the prior 3 months of medical care, which only comprised CaBR and protein/biomaterials. Moreover, none of the long-term transition elements including Pb, Hg, Au, Sn, Sr, Rb, Br, Se and Cr had accumulated in the acute gallbladder sludge but they had found in chronic CaBR gallstone, however, the elements Hf, Co and Ti were present in the acute gallbladder sludge. The levels of Zn, Cu, Mn and Ca were lower in acute gallbladder sludge than in chronic gallstones. Our results indicate that this acute gallbladder sludge comprised large amounts of protein/biomaterials with fewer CaBR aggregates and had different element contents as compared with common chronic gallstones.

We report a potential application of a portable fiber-optic Raman spectroscopy for fast prostatic calculi diagnosis. A portable Raman analyzer with a fiber-optic probe was first used to identify and differentiate the mineral components of prostate stones. The study indicates that three types of stones, hydroxyapatite (HA) stone, calcium oxalate dehydrate (COD) stone and mixed stone including HA, calcium oxalate monohydrate (COM) and COD, were directly detected from 15 patients with prostatic calculi in a short time. The present study reveals that this portable fiber-optic Raman spectroscopic technique was an easy and fast “real-time” tool to differentiate the mineral components in prostatic calculi.

According to the gas dynamic theory, this paper deduces the approximate calculation formula on elastic energy of a tons of coal through theory analysis, and then gets the quantitative calculation method between incident overpressure and reflected overpressure of the coal and gas outburst shock wave. The calculation formula in this paper is in line with the measured values, and so its validity has been verified. The analysis result shows that the effect of the elastic energy during the process of coal and gas outburst should be considered when the depth of the coal seam is great and the coal’s modulus of elasticity is small.

It can be concluded that two abreast near ways were suffered disturbed effects by one another in the cause of one’s excavation by studying the disturbed effects between JI17-22300 air way and machine way of JI16-22320 working face in the course of excavation ofJI17-22300 air way in Pingmei Shares Shikuang. We found three kinds of phenomenons. Firstly, the biggest deformation was the floor. Secondly, the stress concentration zone was10m-20m in front of the head of the roadway and floor drum violent activities for a period of 6-7 days. Lastly, stress appeared on two walls earlier of that of roof and floor stress appearance, namely wall deformation happened in distance of head-on20m, wall deformation amount begins to tend stable convergence after50~60 meters of roadway, those were happened in the roadways which were 450m depth, 11m span and at the drivage speed of 10m/d.

The influence of converter faults to the system is introduced and the fault detection method based on wavelet transform and neural network is proposed in this paper. The fault information can be decomposed by wavelet transform, then the fault eigenvectors can be extracted and put into neural network for training and testing. Finally the neural network outputs specific codes, and thus the fault location and fault components of converters are confirmed, which lays the foundation for the fault-tolerant operation control of converters. Simulation and experimental results show the correctness and effectiveness of the method.

This paper aims to provide an overall image in terms of low carbon society (LCS) and its development in China. It mainly introduced and analyzed low carbon development which was addressed as crucial initiative for implementation of LCS in China. A comparative analysis was carried out on concepts and experiences of LCS between China and developed countries. The trends and characteristics of CO2emissions in China have also been analyzed. Because of large amount of CO2emissions generated in the production process and relatively small amount of CO2emissions in the consumption process, China is facing a severe challenge of imbalance in economic growth and CO2emissions. If the consumption and production pattern of developed countries are duplicated, China is very likely to experience a development pattern of boosting economic growth and improving living standards significantly but meanwhile risking and suffering by large amount of resources consumption and CO2emissions. Thus, a comprehensive, systematic and scientific scheme for implementing a low carbon society is urgently needed in China. Through literature research, mainstream perspectives of scholars with respect to development of LCS are concluded. In the meantime, CO2emissions reduction target, carbon taxation and different debated issues are also presented. The achievements, China has made, consist of concrete actions taken by local governments, some new policies and regulations for carbon reduction at national level, in particular energy-saving and renewable energy policies proposed in the 11th Five-Year Plan (2005–2010). Carbon trading markets and carbon capture and starage technology have also made progress in China. There are still many limitations and barriers remaining and in need to be solved in the next steps.

Soft tissue calcification has been linked to many disease states. Differences in the chemical composition of calcifications not only aid in the understanding of disease onset and progression but also help in correlating with the pathogenesis. A rare case of a huge intra-cardiac calcified lesion within the left atrium of heart was diagnosed in an 80-year-old male patient. Chest CT and X-ray screening, morphological observation, histopathological examination, and Raman spectral analysis of this giant cardiac calculus were investigated. Both chest CT and X-ray images showed a huge lesion with an obvious calcified ring and a shadow that almost completely occupied the left atrium of the heart. The histopathological examination revealed deep blue–purple (H&E) and black (von Kossa) stains of calcium salts interspersed within the non-calcified tissue. Morphologically, this giant cardiac calculus was a hard, brownish-yellow, fist-shaped calculus (about 50×45×30 mm in size) surrounded by a layer of thick white tissue. The brownish-yellow areas on the encrusted surface of the cardiac calculus had a high level of calcium hydroxyapatite after portable Raman spectroscopic detection, but the cholesterol component was predominant in the layer of firm white tissue. Some type-B carbonate apatites and proteins were also identified. The portable Raman spectroscopy with a fiber-optic probe evidenced that this giant cardiac calculus was composed of cholesterol, calcium hydroxyapatite, type-B carbonate apatite and protein.

In this paper, near infrared spectroscopy combined with a wavelength selection method was used to identify fermented vinegar and blended vinegar. Competitive adaptive reweighted sampling (CARS) method was employed to select the key wavelengths. For classification of different vinegars, 11 wavelengths were selected and a PLS-DA model was calculated based on these selected wavelengths. The average error rate (AER) obtained by repeated double cross validation (RPCV) was 6.95%. The results indicated that NIR spectroscopy combined with a wavelength selection method could be applied as a fast alternative method for the identification of different vinegars.

Abstract: Background: The aim of this study was to quickly and quantitatively detect the chemical composition of the calcified deposit on the surface of a surgically excised cornea by using vibrational microspectroscopy. Methods: Both attenuated total reflection (ATR)/Fourier transform infrared (FTIR) and confocal Raman microspectroscopies were used to evaluate the chemical composition of the excised corneal calcified opaque deposit of a 50-year-old male patient. Hydroxyapatite (HA) was used as a reference. Results: Microscopic observations indicated that a whitish-grayish opaque plaquelike deposit was observed. A peak at 1020 cm−1 assigned to the stretching vibration of phosphate of the poorly crystalline, immature and nonstoichiometric HA was observed from the IR spectrum of the corneal calcified deposit, as compared with the peak at 1030 cm−1 of the mature, crystalline and stoichiometric HA reference sample. Higher contents of two IR spectral peaks at 871 cm−1 due to the type-B carbonated apatite and at 866 cm−1 corresponded to a labile carbonate were also evidenced in the corneal calcified deposit. The predominate peak at 959 cm−1 due to the stretching mode of phosphate was also found in the Raman spectrum of corneal calcified deposit. Conclusions: The corneal calcified deposit was evidenced to contain much poor crystalline and immature HA having higher content of the type-B carbonated apatite within the corneal collagen matrix. The process of corneal calcification still proceeds on the surface of this cornea.

Purpose. Enalapril may undergo the thermal-induced intramolecular interaction to cause an enalapril diketopiperazine (DKP) formation. It is interesting to study the influence of Eudragit E, as a coating polymer, on the stability of enalapril maleate. The reaction kinetics of the solid-state degradation process of pure enalapril maleate and Eudragit E/enalapril maleate mixture with different weight ratios were examined. The mechanism of solid-state interaction between Eudragit E and enalapril maleate was also discussed. Methods. The cast samples of pure enalapril maleate or Eudragit E/enalapril maleate mixture after evaporating the solvent were prepared on an aluminum foil and also determined by reflectance Fourier transform infrared (FTIR) microspectroscopy equipped with thermal analyzer. Results. The result indicates that the interaction might occur between enalapril maleate and Eudragit E in the solid state after evaporating the solvent. The thermal-dependent FTIR spectra show that not only the formation of DKP but also the six-membered cyclic anhydride occurred in the enalapril maleate/Eudragit E mixture in the heating process. Two pathways for solid-sate interaction were proposed. The stability of enalapril maleate was dependent on the weight ratio of enalapril maleate and Eudragit E. The activation energy (n = 3) of DKP formation for pure enalapril maleate was about 141.2 ± 0.7 kJ/mol, but it was reduced significantly to 86.7 ± 0.8 kJ/mol after interaction with Eudragit E (weight ratio: 1:1), suggesting Eudragit E might exacerbate the degradation of enalapril maleate. However, the degradation accelerated by Eudragit E was reduced in high content of Eudragit E. Conclusions. When the weight ratio of both components was 1:1, Eudragit E might interact with the carboxyl group of maleic acid to exacerbate the degradation of enalapril maleate. However, the excess amount of Eudragit E might somewhat reduce the degradation of enalapril, due to the interaction that occurred between Eudragit E and carboxyl group of enalapril.

In this review, the concepts of chronobiology, circadian rhythm, chronopharmacology, homeostasis and chronotherapy are taken into account to approach the optimal drug therapy, in which the timing of drug administration plays an important role. Based on these considerations, our laboratory has developed a thermo-responsive membrane by entrapping a single or binary liquid crystal to achieve an on-off switching drug delivery for transdermal application via the externally repeated cycle of temperature change, which may simulate the dosing time of therapeutic needs for human body.

Purpose. The processes of dehydration, rehydration, and solidification of trehalose dihydrate were examined to simulate it in the drying and wetting states. Methods. Techniques included differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and Fourier transform infrared (FT-IR) microspectroscopy combined with thermal analysis. Trehalose dihydrate was pressed on one KBr pellet (1KBr method) or sealed within two KBr pellets (2KBr method) for FT-IR measurement. Results. On the DSC thermogram, the shoulder between 60°C and 80°C represented a transitional change because no weight loss occurred in this area of the TGA curve. The endothermic peak at 100°C represented dehydration of trehalose dihydrate to anhydrous trehalose; a 9.5% weight loss in the TGA curve occurred from 81°C. The thermal-dependent FT-IR spectra for trehalose dihydrate prepared by the 1KBr method changed markedly with temperature in the 1800-1500 cm−1region during dehydration. IR peak intensity at 1687 cm−1assigned to the bending vibrational mode of solid-like water declined with temperature and decreased sharply at 67°C. Another IR peak at 1640 cm−1associated with the bending of liquid water increased at 67°C but disappeared at 79°C as a result of water evaporation. Both peaks for the sample prepared by the 2KBr method changed dramatically at 64°C; peak intensity at 1640 cm−1remained constant above 64°C. Conclusions. A new polymorphic transition of trehalose dihydrate was first evidenced at 64-67°C from both DSC curves and thermal-related FT-IR spectra. This transitional temperature reflected the thermal-dependent transformation from solid-like water to liquid water in the trehalose dihydrate structure during dehydration. During rehydration, trehalose anhydrate was rehydrated to the dihydrate, and liquid water in the dihydrate structure was again transformed to solid-like water. The polymorphic transition within this temperature range seems to correlate with the bioprotective effect of trehalose dihydrate in preserving protein stability.

AbstractSecondary structure of three amyloid β-peptides [Aβ(1–28), Aβ(1–40) and Aβ(1–42)] in the solid state was respectively determined by Fourier transform infrared (FT-IR) microspec- troscopy. Their thermal-dependent structural transformation were also investigated by FT- IR microspectroscopy equipped with a thermal analyzer. The present result demonstrates that the solid-state Aβ(1–28), Aβ(1–40) and Aβ(1–42) peptides showed a significant IR spectral difference in the amide I and II bands. The secondary conformation of Aβ(1–28) peptide was the combination of major β-sheet and minor α-helix with little random coil structures, but Aβ(1–40) peptide showed the co-existence of major β-sheet and minor random coil with little α-helix structures. Aβ(1–42) peptide mainly consisted of the predominant β-sheet structure. Although the intact Aβ(1–28), Aβ(1–40) or Aβ(1–42) peptide exhibits a different secondary structure, a similar β-conformation may form after thermal treatment. A thermal- dependent transition was found for solid Aβ(1–28) and Aβ(1–40) peptides near 40° C and 45° C, respectively. There was no transition temperature for solid Aβ(1–42) peptide, however, due to only a very little level of α-helix and random coil structure containing in the solid Aβ(1–42) peptide. The thermal denaturation plays an important role in the structural transformation from α-helix/random coil to β-sheet.

Fourier transform IR spectroscopy equipped with attenuated total reflection was used to investigate the cysteine-induced alteration of the protein secondary structure of bovine serum albumin (BSA) in aqueous solution before and after UV-B irradiation. Several amino acids were also studied. The results indicate the unchanged IR spectra of BSA coincubated with amino acids, except cysteine, did not change after 72-h UV-B irradiation. There was no difference in the IR spectrum of the unirradiated BSA coincubated with cysteine. A shoulder at 1620 cm⁻¹ attributed to the intermolecular β-sheet structure was observed for the IR spectrum of BSA coincubated with cysteine after 72-h UV-B irradiation. Moreover, the peak intensity at 1303 cm⁻¹ that is due the α-helix structure was reduced, but the peak intensity at 1247 cm⁻¹ corresponding to β-sheet structures was increased. Longer UV-B exposure for a BSA solution coincubated with cysteine changed the BSA solution from clear to viscous to gel form in which a transparent gel and another white gel were simultaneously observed. A gradual IR spectral alteration was found for BSA coincubated with cysteine and subjected to increased UV-B irradiation. The longer UV-B irradiation yielded increased intensity at 1620 cm⁻¹. The second-derivative IR peaks at 1655, 1631, and 1548 cm⁻¹ were shifted to 1650, 1620, and 1544 cm⁻¹, respectively, by the increase of UV-B irradiation, suggesting a progressive transformation from an α-helix to an intermolecular β-sheet structure for BSA coincubated with cysteine. This strongly implies that longer UV-B exposure time for the BSA solution in the presence of cysteine did alter the protein secondary structures of BSA more, thus inducing gel formation by protein aggregation. © 2003 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy) 72: 345–351, 2003

A thermo-responsive membrane was developed by adsorbing the binary liquid crystals (LC) onto the cellulose nitrate membrane. The binary LC mixture is consisted of 36% cholesteric oleyl carbonate (COC) and 64% cholesteryl nonanoate (CN). The physico-chemical and the thermo-responsive properties of this binary LC adsorbed-membrane were examined. The results indicate that the adsorption behavior of binary LC mixture on the cellulose membrane was quick and reached to the equilibrium about 10 min, and linearly correlated with the increase of LC concentration used. The hydrophilic membrane was hydrophobicized after adsorption of binary LC mixture. The focal conic fan textures of binary LC mixture were observed from the surface of cellulose membrane. Due to the obedience and reproducibility of the binary LC used, the binary LC mixture-adsorbed membrane continuously exhibited an on-off thermo-responsive sensitivity to control the drug penetration.

The effect of excipient, drug, and osmotic agent loaded in the inner core tablet on the time‐controlled disintegration of compression‐coated tablet prepared by direct compression with micronized ethylcellulose was investigated. The excipients [spray‐dried lactose, hydroxypropyl methyl cellulose, sodium starch glycolate, microcrystalline cellulose, different drugs (sodium diclofenac: model drug, salbutamol sulfate, and theophylline anhydrate) and osmotic agent (sodium chloride)] were used to formulate the composition of the inner core tablet. The result indicates that drug release from all the compression‐coated tablets was characterized by a distinctive lag of time followed by a faster drug release, dependent on the types of excipient and drug, and osmotic agent used in the inner core tablet. Respectively, the lag of time was 8.5, 12.4, 14.6, or 15.8 h for spray‐dried lactose, hydroxypropyl methyl cellulose, sodium starch glycolate, or microcrystalline cellulose‐loaded inner core tablet, as compared with 16.4 h for an inner core made of sodium diclofenac alone. The direct‐compressible excipients such as spray‐dried lactose, sodium starch glycolate, and microcrystalline cellulose seemed not to illustrate a marked disintegration function to rapidly rapture the outer coating layer. The lag of time was only slightly shortened from 16.4 to 14.6 h, >24 to 17.8 h, or >24 to 21.3 h for sodium diclofenac, theophylline anhydrate, or salbutamol sulfate incorporated with sodium starch glycolate into the inner core tablet, respectively, suggesting that sodium starch glycolate did not perform its superdisintegration. Once an osmotic agent of sodium chloride was incorporated into the inner core tablet, the lag of time for the compression‐coated tablet was markedly shortened to <1 h, as compared with 16.4 h for drug alone. The more the amount of sodium chloride added, the less the time of lag obtained. Osmotic pressure did have a key role in controlling the drug dissolution. The present result implies that osmotic function is more suitable than superdisintegration function in designing a compression‐coated tablet with time‐controlled disintegration. © 2002 Wiley‐Liss Inc. and the American Pharmaceutical Association J Pharm Sci 91:2040–2046, 2002

AbstractThe thermal stability of three superoxide dismutases (SODs) with different metal ions (Mn, Cu/Zn, Fe) in the solid state was studied by a Fourier transform infrared (FT-IR) microspec-troscopy combined with thermal analyzer. The IR spectra showed a maximum peak at 1652 cm−1for all the native SODs in the amide I band, suggesting a predominant random coil with less α-helix structures. By heating each sample, a shoulder at 1631 cm−1in the amide I band gradually appeared from 45° C for Fe SOD and from 50° C for Mn SOD but another shoulder at 1639 cm−1appeared from 50° C for Cu/Zn SOD. The peak at 1631 cm−1is due to the intermolecular β-sheet structure, but the peak at 1639 cm−1corresponds to the major intramolecular β-sheet with less random coil structure. This reveals that in the first heating process the transformation from random coil/a-helix structure to β-sheet structure initiated from around 45–50° C. There was about 16–22% compositional change resulting from that transformation. However, both additional shoulders stood there and did not restore to their original spectra even with cooling to room temperature, suggesting the denaturation and irreversible properties of the solid SODs after heating. The thermal-dependent denaturation and irreversibility of Mn SOD, Cu/Zn SOD and Fe SOD were clearly evidenced by the increase in intramolecular and intermolecular β-sheet structure.

Norfloxacin is a special compound. Its hydrate form seems to be more soluble in water than in the anhydrate form. To investigate the hydration behavior of norfloxacin, the moisture-sorption analysis of anhydrous norfloxacin in different humidities was determined by using differential scanning calorimetry and thermogravimetric analysis. The contents of free water and bound water in the moisture-equilibrated norfloxacin were estimated quantitatively by using a curve-fitting program. Fourier transform infrared microspectroscopy with or without thermal analyzer was used to examine the structural change and dehydration process of norfloxacin in different humidities. The result indicates that the water content sorbed to anhydrous norfloxacin changed lightly below 51% relative humidity (RH) but increased markedly beyond 51% RH. The content of free water in the moisture-equilibrated norfloxacin was nearly to zero below 55% RH, but increased dramatically in high humidity. The content of bound water also enhanced gradually with the external humidity and reached to a constant of one unit after >75% RH. When norfloxacin anhydrate transformed to its hydrate, the infrared peak intensity at 1732 and 1253 cm−1assigned to the C-O and C–O groups of carboxylic acid decreased gradually with the increase of water content, but the infrared peak intensity at 1584 and 1339 cm−1corresponding to asymmetric and symmetric carboxylates increased. Furthermore, the peak at 2553 cm−1assigned to the NH2+also appeared clearly and shifted from 2558 cm−1in higher water content and humidity. The main functional groups of norfloxacin changed from COOH to COO−and NH to NH2+, attributable to the proton transfer from COOH group to NH group. This suggests that the hydration can induce the interaction between norfloxacin molecules from hydrogen bonding to ionic bonding by a proton-transfer process in the solid state. © 2002 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 91:1351–1357, 2002

AbstractThe effect of pressure on the conformational structure of amyloid β (1–40) peptide (Aβ(1–40)), exacerbated with or without temperature, was determined by Fourier transform infrared (FT-IR) microspectroscopy. The result indicates the shift of the maximum peak of amide I band of intact solid Aβ(1–40) from 1655 cm−1(α-helix) to 1647–1643 cm−1(random coil) with the increase of the mechanical pressure. A new peak at 1634 cm−1assigned to β-antipar- allel sheet structure was also evident. Furthermore, the peak at 1540 cm−1also shifted to 1527 (1529) cm−1in amide II band. The former was assigned to the combination of α-helix and random coil structures, and the latter was due to β-sheet structure. Changes in the composition of each component in the deconvoluted and curve-fitted amide I band of the compressed Aβ(1–40) samples were obtained from 33% to 22% for α-helix/random coil structures and from 47% to 57% for β-sheet structure with the increase of pressure, respectively. This demonstrates that pressure might induce the conformational transition from α-helix to random coil and to β-sheet structure. The structural transformation of the compressed Aβ(1–40) samples was synergistically influenced by the combined effects of pressure and temperature. The thermal-induced formation of β-sheet structure was significantly dependent on the pressures applied. The smaller the pressure applied the faster the β-sheet structure transformed. The thermal-dependent transition temperatures of solid Aβ(1–40) prepared by different pressures were near 55–60 °C.

The influence of compression force to inner core tablet or to outer coating layer of the compression-coated tablet on the function of time-controlled disintegration was investigated. The inner core tablet was directly compacted by sodium diclofenac (model drug) and ethylcellulose (EC) with 4.6-μm particle size was used as an outer coating layer. The immersion time of the compression-coated tablet previously soaked in pH 1.2 solution to simulate the residence time of the tablet in the GI tract affecting the dissolution behavior of the compression-coated tablet was also investigated. The effect of the amount of the outer coating layer used on the drug release was examined. The results indicate that sodium diclofenac released from these compression-coated tablets exhibited a longer lag of a period about 16.3 h in both distilled water and pH 6.8 buffer solution, followed by a different drug release behavior. The lag time was independent of the pH of dissolution medium, and the immersion time in pH 1.2 solution. After that lag time, the outer shell of the compression-coated tablets broke into two halves to make a rapid drug release. However, the drug release behavior of the soaked tablet in pH 6.8 buffer solution was dependent on the immersion time. The compression force &lt; 200 kg/cm² to the inner core tablet influenced the release behavior of drug less, but > 200 kg/cm² might delay the lag time. The lag time of the compression-coated tablets was linearly correlated with the compression force to the outer coating layer (r = 0.9896). We also found that the more the amount of outer coating layer added, the longer the lag time obtained. The study demonstrates that the time-controlled disintegration of the compression-coated tablet was effectively controlled by the compression force applied and the amount of outer coating layer added. © 2001 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 90:2005–2009, 2001

Thermal Fourier transform infrared (FT-IR) microspectroscopy was used to investigate the conformational isomerization of captopril in the solid state. The result indicates that the IR peak intensity of captopril for original bands decreased dramatically at 102°C, but for new bands it increased with the rise of temperature. The frequency of C&dbond;O stretching mode for carboxylic acid and for amide was located at a higher wavenumber of 1747 cm^− 1 and at a lower frequency of 1591 cm^− 1 as compared with the general compound, suggesting the existence of trans isomer of captopril in the solid state by intramolecular hydrogen bonding. Beyond 102°C, several new bands at 1720, 1645, and 1610 cm^− 1 were observed with the rise of temperature, indicating the coexistence of a cis isomer. However, the cis isomer could transform gradually to the trans isomer after cooling. The thermodynamics of equilibrium mixture of cis/trans isomers were also studied. The trans isomer was more stable than the cis isomer, but the cis isomer was favored at the higher temperature. © 2001 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 90:1034–1039, 2001

Thermal Fourier transform infrared (FT-IR) microspectroscopy was used to investigate the conformational isomerization of captopril in the solid state. The result indicates that the IR peak intensity of captopril for original bands decreased dramatically at 102°C, but for new bands it increased with the rise of temperature. The frequency of C=O stretching mode for carboxylic acid and for amide was located at a higher wavenumber of 1747 cm− 1and at a lower frequency of 1591 cm− 1as compared with the general compound, suggesting the existence of transisomer of captopril in the solid state by intramolecular hydrogen bonding. Beyond 102°C, several new bands at 1720, 1645, and 1610 cm− 1were observed with the rise of temperature, indicating the coexistence of a cisisomer. However, the cisisomer could transform gradually to the transisomer after cooling. The thermodynamics of equilibrium mixture of cis/transisomers were also studied. The transisomer was more stable than the cisisomer, but the cisisomer was favored at the higher temperature. © 2001 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 90:1034–1039, 2001

The purpose of this study is to examine the applicability of an infared spectroscopic methodology for the study of an environmental problem. The effect of cyanide concentrations on the biophysical conformation of the fish liver homogenate was determined by using an attenuated total reflectance (ATR)/Fourier nfrared (FT-IR) microspectroscopy. Alive male model fish, Tilapia Zillii, was used. The liver from fish was isolated and homogenized in pH 8.0 Tris buffer solution. The results indicate that the IR peak intensity increased markedly in the C–H stretching range (3000–2800 cm−1), ester C=O stretching of lipids (1743 cm−1) and carbohydrate bands (1195–950 cm−1), but decreased in the amide I at 1649 cm−1and the free asymmetric stretching band of phosphate at 1261 cm−1with the increase of KCN concentrations. The marked release of hepatic enzymes and glutathione into homogenate induced by cyanide might account for the higher IR spectral peak intensity of fish liver tissue after treatment with KCN. The cyanide was also found to induce the protein structure of fish liver homogenate from α-helical conformation to β-conformation.

Assessment of coastal vulnerability to future environmental change has been emphasized in coastal nations or regions. The Jiangsu coastal plain, located to the north of the Yangtze River Delta in China, is most vulnerable to sea level rise and exacerbating coastal hazards. This paper develops the method of delimiting vulnerable scope and assessing coastal vulnerability through field observations and sampling and by applying remote sensing and GIS, which are suitable for great river delta and coastal plains with large area, relative complex micro-geomorphology and the protection of seawall. Applying this method, the coastal vulnerability of the Jiangsu coastal plain to relative sea level rise (approximately 50 cm up to the year 2050) and exacerbating storm surges have been assessed. The results show that, up to the year 2050, the Jiangsu coastal plain will probably lose 12.8 % of tidal flats (about 5.8x104hm2) and 7.9 % of cultivated land (about 7.2x104hm2). Meanwhile, 2.0 % of population, 3.8 % of original value of fixed assets, 3.2% of GDP (Gross Domestic Product), 40.3 % of salt industry and 5.8 % of aquiculture respectively will be affected due to coastal environmental change.

The effect of skin-penetrating enhancers such as propylene glycol (PG), Azone and ethanol on the thermophysical properties of cholesteryl oleyl carbonate (COC) was investigated using differential scanning colorimetry (DSC) and microscopic Fourier-transform infrared (FT-IR) spectroscopy. The results indicate that PG did not influence the DSC thermograms and IR spectra of COC in the different ratios of COC and PG mixture; whereas Azone interacted with COC not only to lower the semectic-cholesteric phase transition temperature of COC but also to induce a new IR spectral peak at cm-11653cm-1which shifted from the carbonyl stretching band (cm-11636 cm-1) of Azone. Ethanol did not interact with COC, but it influenced the IR spectral peak intensity of COC at cm-11253cm-1. The peak intensity at cm-11253cm-1gradually rose with the time of ethanol evaporation and was similar to that of the temperature effect. The solubility parameter was also used to explain the miscibility and interaction between COC and PG, Azone or ethanol. © 2000 Kluwer Academic Publishers

The thermal stability of Eudragits RL, RS, E 30D, and E films was qualitatively investigated by the reflectance Fourier transform infrared microspectroscopy equipped with differential scanning calorimetry (FTIR/DSC microscopic system). DSC and thermogravimetric analysis (TGA) were also used to study the thermal behavior of the granules of the raw material and the film of these polymers. The results indicate that the Eudragit RL, RS, or E 30D polymer exhibited a higher thermal-stable behavior, but Eudragit E easily formed the six-membered cyclic anhydride through heating process via the inter- or intramolecular ester condensation. The leaving group in Eudragit E molecule was larger than that in Eudragit E 30D, and the leaving group of salt in Eudragit RS or RL was too stable to polycondense. The DSC thermograms and TGA curve also confirmed this result. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 829–835, 2000

The solid-state stability of aspartame hemihydrate (APM) sweetener during thermal treatment is important information for the food industry. The present study uses the novel technique of Fourier transform infrared microspectroscopy equipped with differential scanning calorimetry (FT-IR/DSC microscopic system) to accelerate and determine simultaneously the thermaldependent impurity formation of solid-state APM. The results indicate a dramatic change in IR spectra from 50, 110 or 153°C, which was respectively attributed to the onset temperature of water evaporation, dehydration and cyclization processes. It is suggested that the processes of dehydration and intramolecular cyclization occurred in the solid-state APM during the heating process. As an impurity, 3-carboxymethyl-6-benzyl-2,5-diketopiperazine (DKP) degraded from solid state APM via intramolecular cyclization and liberation of methanol. This was evidenced by this novel FT-IR/DSC microscopic system in a one-step procedure.

The influence of skin-penetrating enhancers such as Azone, ethanol and propylene glycol (PG) on the on-off switching penetration behavior of salbutamol sulfate through the thermo-responsive cholesteryl oleoyl carbonate (COC)-embedded membrane with or without application to the excised nude mice skin was examined. Without the nude mice skin, gel formulations without any enhancer and with Azone showed higher drug penetration across the COC-embedded membrane than those with ethanol and propylene glycol (PG). Moreover, the on-off switching function of COC-embedded membrane still existed. These results indicate that Azone did not alter the thermo-responsive property of COC-embedded membrane. A lower penetration behavior associated with ethanol or PG was probably due to the increased solubility of salbutamol sulfate in each gel formulation and improved drug-carbopol gel interaction. The application of COC-embedded membrane to excised nude mice skin resulted in a similar on-off switching penetration behavior to the gel, but the penetration was significantly weakened compared to the gel formulation that only penetrated through the COC-embedded membrane. However, passage of salbutamol sulfate across the COC-embedded membrane applied to the excised nude mice skin was severely restricted when an enhancer was absent from the gel. Obviously, the excised skin was the predominant barrier to drug penetration. The present study suggests that skin-penetrating enhancer does not alter the structure of the COC embedded in membrane to change the thermo-responsive on-off switching penetration behavior of salbutamol sulfate from gel formulas through COC-embedded membrane.

The aim of this study was to analyze the content of hypnotic components in the essential oil from Citrus aurantiumflowers (EDD), extracted by different methods, and to characterize its sedative-hypnotic effects. The sedative-hypnotic capacity of EDD was evaluated using pentobarbital-induced sleeping assays, locomotor activity tests and GABAAreceptor antagonists. The results showed that EDD extracted by steam and water distillation (SWD), hydrodistillation (HD), and ultrasound-assisted hydrodistillation (UHD) had as their main components linalool, linalyl acetate, and limonene, comprising more than 55% of the total peak area. Compared with EDD extracted by HD and UHD, the total content of linalool and linalyl acetate in EDD obtained by SWD was highest, whereas the content of limonene in EDD extracted by the 3 different methods was not different. Oral and intraperitoneal administration of EDD resulted in reduced sleep latency and increased sleep duration of mice, as well as reduced locomotor activity, which was proven by decreases in the total distance travelled, average velocity, number of activities, and central distance. Interestingly, intraperitoneal injection of EDD had better sedative and hypnotic effects than oral ingestion. In vitro assays using SH-SY5Y cells showed that EDD dose-dependently increased Cl−influx, which could be blocked by the GABAAreceptor antagonists, picrotoxin, bicuculline, and flumazenil, suggesting that EDD promoted sedative-hypnotic activity by potentiating GABAAreceptor-mediated Cl−current responses. Altogether, these results suggest that the important hypnotic-sedative activity of EDD appears to be due to the effects of limonene, and particularly the high contents of linalool and linalyl acetate, which were effectively extracted by SWD.

The thermal stability of the powder or film forms of Eudragits L, S, and L30D and carbopol polymers was qualitatively investigated by microscopic reflectance Fourier transform infrared spectroscopy equipped with differential scanning calorimetry (FT-IR/DSC microscopic system). DSC and thermogravimetric analysis (TGA) were also used to study the thermal behavior of the pulverized powders of the raw material and the films of these polymers. The results indicate that a 6-membered ring cyclic anhydride formation was respectively produced by a heating process in the molecular structures of Eudragits L, S, and L30D and carbopol polymers via inter- or intrapolymer condensation. The peak intensity of the carbonyl stretching absorption of cyclic anhydride-related IR peaks appeared sharply near 1801 and 1759 (1751) cm⁻¹, and a peak near 1006 (1018) cm⁻¹ related to the antisymmetric stretching mode of C&bond;O&bond;C also appeared suddenly beyond the marked reaction temperature. The initial reaction temperature of anhydride formation for the Eudragits L, S, and L30D and carbopol polymers was observed respectively from near 186, 180, 170, and 100°C, whereas the rapid and marked reaction temperature from about 206, 188, 170, and 183°C appeared accurately from the reflectance FT-IR spectra. The DSC thermograms and TGA curves also confirmed these results. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2061–2067, 1999

AbstractThe influence of ultraviolet B (UVB) irradiation on the skin moisture contents, skin color, and protein secondary structure in the skin of alive Sprague-Dawley (SD) rats was investigated. The UVB irradiation source emitted 725 ± 10 μW/cm2of UVB range with a peak at 302 nm during the exposure course of 6 h/day for 3 successive days. The moisture content of SD rat’s skin first decreased with the UVB irradiation, then returned to normal level on days 1 and 2, and, finally, decreased significantly with the increase of UVB irradiation on day 3. After the 6-hour irradiation on days 1 and 2, the moisture contents of the irradiated skin of SD rat returned to normal values, suggesting repairability of the irradiated skin of SD rat during the following 18 hour period without irradiation. By increasing frequency and duration of UVB irradiation, the skin color parameters exhibited a lower L* value, a greater a* value, and a higher ΔE value, indicating that the skin color darkened and reddened. The slight modification of protein secondary structure of the skin of SD rats after repeated UVB irradiation was evidenced. However, the infrared spectrum during the initial course of irradiation, from day 1 to day 3, exhibited a similar pattern. Thus, the alive SD rat’s skin was repairable during the 18-hour period without irradiation.