Impaired function of skeletal stem cells derived from growth plates in ovariectomized mice.

INTRODUCTION: Mouse skeletal stem cells (mSSCs, CD45-Ter119-Tie2-CD51+Thy-6C3-CD105-CD200+population) are identified in growth plates (GP) and play important roles in bone regeneration. However, the role of mSSCs in osteoporosis remains unclear. MATERIALS AND METHODS: The GP were stained by HE staining, and the mSSC lineage was analyzed by flow cytometry at postnatal of 14 days and 30 days in wild-type mice. The mice (8 weeks) were either sham operated or ovariectomy (OVX) and then sacrificed at 2, 4 and 8 w. The GP were stained by Movat staining, and mSSC lineage was analyzed. Then, mSSCs were sorted by fluorescence-activated cell sorting (FACS); the clonal ability, chondrogenic differentiation and osteogenic differentiation were evaluated, and the changed genes were analyzed by RNA-seq. RESULTS: The percentage of mSSCs were decreased with the narrow GP. Heights of GP were decreased significantly in 8w-ovx mice compared with 8w-sham mice. We found the percentage of mSSCs were decreased in mice at 2w after ovx, but the cell numbers were not changed. Further, the percentage and cell numbers of mSSCs were not changed at 4w and 8w after ovx. Importantly, the clonal ability, chondrogenic differentiation and osteogenic differentiation of mSSCs were impaired at 8w after ovx. We found 114 genes were down-regulated in mSSCs, including skeletal developmental genes such as Col10a1, Col2a1, Mef2c, Sparc, Matn1, Scube2 and Dlx5. On the contrary, 526 genes were up-regulated, including pro-inflammatory genes such as Csf1, Nfkbla, Nfatc2, Nfkb1 and Nfkb2. CONCLUSION: Function of mSSCs was impaired by up-regulating pro-inflammatory genes in ovx-induced osteoporosis.

Three novel structural variations at the major histocompatibility complex and IL12B predispose to psoriasis.

BACKGROUND: Structural variations (SVs; defined as DNA variants ≥ 50 base pairs) have been associated with various complex human diseases. However, research to screen the whole genome for SVs predisposing to psoriasis is lacking. OBJECTIVES: To investigate the association of SVs and psoriasis. METHODS: Using imputation, we performed a genome-wide screen of SVs on five independent cohorts with 45 386 participants from the Han Chinese population. Fine-mapping analysis, genetic interaction analysis and RNA expression analysis were conducted to explore the mechanism of SVs. RESULTS: In total, we obtained 4535 SVs and identified two novel deletions [esv3608550, odds ratio (OR) 2·73 (P < 2·00 × 10-308 ); esv3608542, OR 0·47 (P = 7·40 × 10-28 )] at 6q21·33 (major histocompatibility complex), one novel Alu element insertion [esv3607339; OR 1·22 (P = 1·18 × 10-35 )] at 5q33·3 (IL12B) and confirmed one previously reported deletion [esv3587563; OR 1·30 (P = 9·52 × 10-60 )] at 1q21·2 (late cornified envelope) for psoriasis. Fine-mapping analysis including single-nucleotide polymorphisms (SNPs) and small insertions/deletions revealed that esv3608550 and esv3608542 were independently associated with psoriasis, and a novel independent SNP [rs9378188; OR, 1·65 (P = 3·46 × 10-38 )] was identified at 6q21·33. By genetic interaction analysis and RNA expression analysis, we speculate that the association of two deletions at 6q21·33 with psoriasis might relate to their influence on the expression of HLA-C. CONCLUSIONS: We have constructed the most comprehensive SV map for psoriasis thus far and enriched the genetic architecture and pathogenesis of psoriasis, and highlight the non-negligible impact of SVs on complex diseases.

A topical emollient mitigates the progression of cognitive impairment in the elderly: a randomized, open-label pilot trial.

BACKGROUND: Cognitive impairment is common in the elderly. Prior studies suggest a link between chronic inflammation and cognitive dysfunction, while aging-associated epidermal dysfunction has been connected to elevations in circulating cytokines. OBJECTIVE: We assessed here whether improvements in epidermal function can mitigate the progression of cognitive impairment. METHODS: This randomized, open-label pilot trial was carried out in two cities in northern China. A total of 200 participants aged ≥65 years were randomly assigned to the emollient-treated and untreated groups at 1:1 ratio. Participants in the treated group were treated topically with Atopalm cream® twice-daily from November to the following May each year for three consecutive years, while the untreated subjects served as controls. The Global Deterioration Scale (GDS) was used to assess the severity of cognitive impairment, while epidermal biophysical properties were measured on the forearms and the shins in parallel. RESULTS: Over the three-year trial, GDS significantly increased from baseline (P < 0.0001) in the controls, while in the treated group, GDS stabilized. While stratum corneum hydration on the forearms did not change significantly in the controls, transepidermal water loss rates (TEWL), significantly increased by the end of the trial compared to baselines in the controls (P < 0.0001). On the forearms of the treated group, stratum corneum hydration increased (P < 0.0001) while skin surface pH decreased from baseline (P < 0.0001). CONCLUSIONS: These results suggest that improvements in epidermal function with topical emollient can mitigate the progression of cognitive impairment. However, the sample size was relatively small, and trials in a larger cohort are needed to validate the present results.

Comparison of therapeutic efficacy and mechanism of paclitaxel alone or in combination with methotrexate in a collagen-induced arthritis rat model.

OBJECTIVE: To compare the therapeutic efficacy of paclitaxel (PTX) alone to its combination with methotrexate (MTX) on rheumatoid arthritis. METHODS: A collagen-induced arthritis (CIA) rat model was established by induction of type II collagen. Rats were divided into blank control group, CIA model group, MTX group 1 mg/kg, PTX 1.5 mg/kg, PTX 2.5 mg/kg, PTX 3.5 mg/kg, and MTX 1 mg/kg + PTX 3.5 mg/kg, with 10 rats per group. The inflammation of the ankle joint was analyzed by H&E staining and interleukin (IL)-1ß and IL­6 expression was detected by immunohistochemistry. TUNEL assay was performed to detect synovial tissue cell apoptosis after administration of PTX and MTX either alone or in combination. TLR4 and p­NF-κBp65 protein expression in synovial tissue and the changes of serum IL­1ß, IL­6, IL­12, MMP­3, and TNFα protein factors were detected by western blot and ELISA, respectively. RESULTS: PTX and MTX improved histopathological changes in CIA rats. Besides, the apoptosis rate of synovial tissue cells in the PTX 3.5 mg/kg group was more than that of the PTX + MTX group. Immunohistochemistry and western blot results indicated that PTX and MTX reduce the expression rate of IL­6 and IL­1ß and downregulate TLR4 and p­NF-κBp65 protein expression. Furthermore, TLR4 and p­NF-κBp65 reduced the concentration of MMP­3, IL­12, IL­6, IL1­ß, and TNFα. CONCLUSION: Both PTX and MTX exert significant suppression on rheumatoid arthritis, and the combined effect of the two drugs is weaker than that of PTX alone. Moreover, intraperitoneal injection of PTX 3.5 mg/kg every other day was the optimal dose observed in this study.

The impacts of gene polymorphisms on methotrexate in Chinese psoriatic patients.

BACKGROUND: Methotrexate (MTX) is the first-line treatment for psoriasis in China. The metabolic processes of MTX include various proteins and genes. Previous studies have shown that gene polymorphisms had significant impacts on the efficacy of MTX. However, the influence of gene polymorphisms has not been reported in the Chinese psoriatic patients. OBJECTIVE: The aim of this study was to verify the impacts of candidate genes polymorphisms on the effectiveness of MTX in a Chinese psoriatic population. METHODS: In this study, we enrolled 259 psoriasis patients from two clinical centres. Each of them received MTX treatment at 7.5-15 mg/week for at least 8 weeks. Patients were stratified as responders and non-responders according to whether the Psoriasis Area and Severity Index score declined more than 75% (PASI75). According to previous reports, 16 single nucleotide polymorphisms (SNPs) were selected and genotyped for each patient using the Sequenom platform. Fisher's exact test, the chi-square test, Mann-Whitney tests and ANOVA analyses were used for statistical analysis. RESULTS: Among 259 patients, there were 182 males and 77 females, 63 patients with psoriatic arthritis and 196 patients without arthritis phenotype, and the age of all patients ranged from 19 to 70 years (49.7 ± 13.6). The baseline PASI value of patients was 13.8 ± 8.5, and 33.2% of patients achieved a PASI75 response after MTX treatment. Patients carrying the ATP-binding cassette subfamily B member 1 gene (ABCB1) rs1045642 TT genotype were associated with more severe psoriasis skin lesion (P = 0.032). Furthermore, the ABCB1 rs1045642 TT genotype was found to be more frequent in non-responders (P = 0.017), especially in moderate-to-severe patients (P = 0.002) and patients without psoriatic arthritis (P = 0.026) after MTX treatment. CONCLUSION: We have demonstrated for the first time that polymorphism of the ABCB1 rs1045642 TT genotype is predictive of a worse clinical response of skin lesions to MTX therapy in a Chinese psoriatic population.

Improvements in epidermal function prevent relapse of psoriasis: a self-controlled study.

While therapeutic approaches for psoriasis are widely available, preventive regimens are lacking. We aimed to determine whether improvements in epidermal function could prevent psoriasis relapse. Two self-controlled cohort studies were designed, enrolling two cohorts of patients with psoriasis (n = 30 and n = 60) to be treated topically with an in-house-prepared emollient or ATOPALM® cream applied twice daily to one forearm for 20 and 30 days, respectively, while the same sites on the contralateral arm served as the untreated control. Epidermal function on both arms was assessed prior to and at the end of the trials. Delayed relapse on the treated arm was seen in 54.5% and 71% of patients in the first and second cohort, respectively. The time of psoriatic relapse correlated with the extent of abnormalities in baseline epidermal function. These results suggest that improvements in epidermal function with topical emollients can prevent/attenuate the development of psoriasis.

TRIM31 promotes proliferation, invasion and migration of glioma cells through Akt signaling pathway.

This study is intended to investigate the role of Tripartite Motif (TRIM) 31 in glioma. Immunohistochemistry and western blot analysis showed that TRIM31 was overexpressed in high-grade glioma tissues. Univariate survival analysis indicated that high expression of TRIM31 was related to short survival time of glioma patients. Multivariate survival analysis demonstrated that TRIM31 was an independent prognostic factor for glioma patients. In addition, through the experiments on glioma cell lines, we found that after silencing or overexpressing TRIM31 expression, the proliferation, invasion and migration of glioma cells could be downregulated or upregulated through Akt signaling pathway. In short, our study suggests that TRIM31 may be an effective target for glioma intervention.

Validation of GPSkin Barrier® for assessing epidermal permeability barrier function and stratum corneum hydration in humans.

BACKGROUND: Measurements of transepidermal water loss (TEWL) and stratum corneum (SC) hydration are important for assessing epidermal functions. However, the availability of reliable and user-friendly devices, which can simultaneously measure both TEWL and SC hydration and can allow health providers to remotely access data in time, is limited. MATERIALS AND METHODS: GPSkin Barrier® was compared with MPA5 system in the measurements of TEWL and SC hydration on the cheek, the dorsal hand, and the forearm in 200 normal volunteers, including 126 females and 74 males, aged 1-78 years with an average age of 45.24 ± 1.04 years. Correlation of data measured with MPA5 system and GPSkin Barrier® was determined. RESULTS: Levels of both TEWL and SC hydration measured with the Barrie GPSkin Barrier® were lower than that with MPA5 system on all 3 body sites except for hydration on the cheek. The levels of both TEWL and SC hydration measured with GpSkin Barrier® were correlated well with that measured with MPA5 system on all 3 body sites CONCLUSIONS: GPSkin Barrier® is a reliable, affordable, and versatile device for assessing epidermal permeability barrier function and SC hydration.

Topical applications of an emollient reduce circulating pro-inflammatory cytokine levels in chronically aged humans: a pilot clinical study.

BACKGROUND: While increased levels of circulating inflammatory cytokines in chronologically aged humans have been linked to the development of ageing-associated chronic disorders (e.g., cardiovascular disease, type II diabetes, osteoporosis and Alzheimer's disease), approaches that reduce circulating cytokines are not yet available. In chronologically aged mice, we recently demonstrated that epidermal dysfunction largely accounts for age-associated elevations in circulating cytokine levels, and that improving epidermal function reduced circulating cytokine levels. OBJECTIVE: We performed a pilot study to determine whether improving epidermal function reduces circulating pro-inflammatory cytokine levels in aged humans. METHODS: Thirty-three aged humans were topically treated twice-daily for 30 days, with ≈ 3 mL of an emollient, previously shown to improve epidermal function, while untreated, aged humans and a cohort of young volunteers served as controls. Changes in epidermal function and levels of three key, age-related, plasma cytokines (IL-1ß, IL-6 and TNFα) were measured at baseline and after treatment, using Luminex 200™ system. RESULTS: We also found significantly higher baseline levels of IL-1ß, IL-6 and TNFα in aged vs. young humans (P < 0.001), as previously reported. Topical applications of the barrier repair emollient significantly enhanced epidermal permeability barrier function (P < 0.01) and stratum corneum hydration (P < 0.05). In parallel, circulating levels of IL-1ß and IL-6 normalized, while TNFα levels declined substantially. CONCLUSION: The results of this preliminary study suggest that a larger clinical trial should be performed to confirm whether improving epidermal function also can reduce circulating pro-inflammatory cytokine levels in aged humans, while also possibly attenuating the downstream development of chronic inflammatory disorders in the aged humans.

Randomized phase II trial comparing tumor bed alone with tumor bed and elective nodal postoperative radiotherapy in patients with locoregionally advanced thoracic esophageal squamous cell carcinoma.

This study compares the outcomes of different postoperative radiation fields for locoregionally advanced thoracic esophageal squamous cell carcinoma (ESCC) patients. This is a multi-institution randomized phase II trial and noninferior study. Patients with ESCC who had undergone esophagectomy (stage T3-4N0-3M0) were enrolled and randomized into the large-field irradiation arm (LFI; tumor bed and elective lymph node region) and small-field irradiation arm (SFI; tumor bed only). The primary endpoint was whether the disease-free survival (DFS) of SFI was not inferior to LFI. The secondary endpoint was to evaluate the rationality of the radiation target volume by analyzing failure patterns. One hundred twenty-one patients (64 patients for LFI and 57 patients for SFI, respectively) were eligible in this mid-time analysis. The 1- and 3-year DFS was 79.9%, 46.2% for LFI and 67.6%, 44.3% for SFI, respectively (P = 0.414). The locoregional recurrence-free survival (LRFS) of LFI was significantly better than that of SFI (P = 0.003). However, there were no significant differences in the distant metastasis-free survival and overall survival between the two arms (P = 0.332, P = 0.405, respectively). The failure patterns of the two arms were significantly different (P = 0.002). For pT3-4N0-3M0 ESCC patients, postoperative radiotherapy with SFI showed a similar survival outcome to LFI. However, the LRFS of patients with SFI was worse than that of patients with LFI.

Limb-salvage treatment of malignant tumors of the limbs.

The aim of this study was to explore the clinical efficacy of limb-salvage therapy for malignant bone tumors of the limbs using two surgical methods. This investigation presents a retrospective study of malignant bone tumors of the limbs in 42 patients. Participants were divided into two groups: group A of 25 patients who were treated with artificial prosthesis replacement, and group B of 17 patients treated with bone inactivation. By collection of clinical data, the survival rate, surgical complications, quality of life, pain relief and postoperative limb function following artificial prosthesis replacement and tumor inactivation were comprehensively evaluated in patients with malignant bone tumors of the limbs. Group A had significantly higher Karnofsky quality of life scores compared to group B after six months (P=0.027). The Enneking scores of limb functions in group A were significantly higher than those of group B (P=0.022). In group A the postoperative limb function score was good and excellent in 92% and in group B in 64.7%. There were significantly more postoperative complications in group B compared with group A (P=0.027), but no significant difference in the recurrence rate in the two group (P=0.976). The study results can provide reference for surgical treatment of the patients with malignant bone tumors.

Concurrent chemoradiotherapy for cervical esophageal squamous cell carcinoma: treatment results from a prospective observational study.

A prospective observational study was performed to evaluate the results of treatment with concurrent chemoradiotherapy (CCRT) in patients with cervical esophageal squamous cell carcinoma (CESCC). Patients had CESCC, no distant metastasis, were 18-75 years old, and had PS 0-2. Radiotherapy (RT) was administered as either three-dimensional conformal radiation therapy (3D-CRT) or intensity-modulated radiation therapy (IMRT) with a total dose of 60 Gy/30 fractions. All patients were treated with platinum-based doublet concurrent chemotherapeutic regimens. CCRT was followed by 2-3 cycles of consolidation chemotherapy. The endpoints were overall survival (OS), progression-free survival (PFS), toxicities, and failure patterns. Ninety-two patients were enrolled from March 2007 to July 2014. The median follow-up time was 34 months. For all patients, the 3-year OS was 49.8% (median OS: 36 months, 95% CI: 24.963-47.051), and the 3-year PFS was 42.1%, (median PFS: 25 months, 95% CI: 17.097-32.903). Treatment failures occurred in 54 patients, including 30 cases (32.6%) with locoregional failure alone, 14 cases (15.2%) with distant metastasis alone, and 10 cases (10.9%) with both locoregional failure and distant metastasis. There were 51 (55.4%) and 3 cases (3.3%) of grade 3 and grade 5 radiation esophagitis, respectively. One patient (1%) had grade 5 laryngeal edema. Overall, CCRT has tolerable acute toxicities, and this regimen is an option for the treatment of patients with CESCC.

[High mobility group box 1 promotes apoptosis of astrocytes after oxygen glucose deprivation/reoxygenation by regulating the expression of Bcl-2 and Bax].

OBJECTIVE: To investigate the effect of high mobility group protein box 1 (HMGB1) on apoptosis of astrocytes after oxygen glucose deprivation/reoxygenation (OGD/R), and to investigate the possible mechanism by evaluating the expression of apoptosis related protein Bcl-2 and Bax. METHODS: The cerebral cortex astrocytes of neonatal rats were divided into normal group, model group, interference group and control group. Lentivirus vector of rat HMGB1 short hairpin RNA (shRNA) was used to suppress the HMGB1 protein expression in the astrocytes. Then the detection was made after astrocytes were deprived of oxygen and glucose 6 h, reoxygenation for 24 h. The effect of RNA interference was evaluated by Western blotting. The cell survival rate was measured by MTT assay. The apoptosis of astrocytes was determined by TUNEL assay. The expressions of Bcl-2 and Bax were detected by Western blotting. RESULTS: Compared with the normal group, the protein expression of HMGB1 was significantly increased in model group after OGD/R (P<0.001), the astrocytes survival rate was decreased (P<0.001), the number of apoptotic cells labeled with TUNEL was increased (P<0.001), and the ratio of Bcl-2/Bax was decreased (P<0.001). Compared with the model group, RNA interference effectively inhibited the expression of HMGB1 in interference group (P<0.001), the astrocytes survival rate was increased (P<0.001), the number of apoptotic cells labeled with TUNEL was reduced (P<0.01), and the ratio of Bcl-2/Bax was increased (P<0.001). CONCLUSION: The apoptosis of astrocytes can be induced by HMGB1 after OGD/R, and the mechanism may be related to regulating the expression of apoptosis related proteins Bcl-2 and Bax.

[Construction of chemical information database based on optical structure recognition technique].

OBJECTIVE: To create a protocol that could be used to construct chemical information database from scientific literature quickly and automatically. METHODS: Scientific literature, patents and technical reports from different chemical disciplines were collected and stored in PDF format as fundamental datasets. Chemical structures were transformed from published documents and images to machine-readable data by using the name conversion technology and optical structure recognition tool CLiDE. In the process of molecular structure information extraction, Markush structures were enumerated into well-defined monomer molecules by means of QueryTools in molecule editor ChemDraw. Document management software EndNote X8 was applied to acquire bibliographical references involving title, author, journal and year of publication. Text mining toolkit ChemDataExtractor was adopted to retrieve information that could be used to populate structured chemical database from figures, tables, and textual paragraphs. After this step, detailed manual revision and annotation were conducted in order to ensure the accuracy and completeness of the data. In addition to the literature data, computing simulation platform Pipeline Pilot 7.5 was utilized to calculate the physical and chemical properties and predict molecular attributes. Furthermore, open database ChEMBL was linked to fetch known bioactivities, such as indications and targets. After information extraction and data expansion, five separate metadata files were generated, including molecular structure data file, molecular information, bibliographical references, predictable attributes and known bioactivities. Canonical simplified molecular input line entry specification as primary key, metadata files were associated through common key nodes including molecular number and PDF number to construct an integrated chemical information database. RESULTS: A reasonable construction protocol of chemical information database was created successfully. A total of 174 research articles and 25 reviews published in Marine Drugs from January 2015 to June 2016 collected as essential data source, and an elementary marine natural product database named PKU-MNPD was built in accordance with this protocol, which contained 3 262 molecules and 19 821 records. CONCLUSION: This data aggregation protocol is of great help for the chemical information database construction in accuracy, comprehensiveness and efficiency based on original documents. The structured chemical information database can facilitate the access to medical intelligence and accelerate the transformation of scientific research achievements.

Etoposide and cisplatin versus paclitaxel and carboplatin with concurrent thoracic radiotherapy in unresectable stage III non-small cell lung cancer: a multicenter randomized phase III trial.

Background: The optimal chemotherapy regimen administered currently with radiation in patients with stage III non-small cell lung cancer (NSCLC) remains unclear. A multicenter phase III trial was conducted to compare the efficacy of concurrent thoracic radiation therapy with either etoposide/cisplatin (EP) or carboplatin/paclitaxel (PC) in patients with stage III NSCLC. Patients and methods: Patients were randomly received 60-66 Gy of thoracic radiation therapy concurrent with either etoposide 50 mg/m2 on days 1-5 and cisplatin 50 mg/m2 on days 1 and 8 every 4 weeks for two cycles (EP arm), or paclitaxel 45 mg/m2 and carboplatin (AUC 2) on day 1 weekly (PC arm). The primary end point was overall survival (OS). The study was designed with 80% power to detect a 17% superiority in 3-year OS with a type I error rate of 0.05. Results: A total of 200 patients were randomized and 191 patients were treated (95 in the EP arm and 96 in the PC arm). With a median follow-up time of 73 months, the 3-year OS was significantly higher in the EP arm than that of the PC arm. The estimated difference was 15.0% (95% CI 2.0%-28.0%) and P value of 0.024. Median survival times were 23.3 months in the EP arm and 20.7 months in the PC arm (log-rank test P = 0.095, HR 0.76, 95%CI 0.55-1.05). The incidence of Grade ≥2 radiation pneumonitis was higher in the PC arm (33.3% versus 18.9%, P = 0.036), while the incidence of Grade ≥3 esophagitis was higher in the EP arm (20.0% versus 6.3%, P = 0.009). Conclusion: EP might be superior to weekly PC in terms of OS in the setting of concurrent chemoradiation for unresectable stage III NSCLC. Trial registration ID: NCT01494558.

The occurrence of the strongylid nematodes Kalicephalus brachycephalus, K. bungari and K. indicus in snake species from Hunan Province, China.

Kalicephalus is a genus of strongylid nematodes infecting snakes and causing serious diseases and even death when it is complicated with secondary bacterial infections. The infection of snakes with Kalicephalus has been reported in many countries in the world. However, little information is available on the prevalence of Kalicephalus in snakes in China. In the present study, the prevalence of Kalicephalus in snakes was investigated. The worms were examined, counted and identified to species according to existing keys and descriptions. Three species of Kalicephalus, namely K. indicus, K. bungari and K. brachycephalus, were found in six species of snakes (Elaphe carinata, Zaocys dhumnade, Naja najaatra, Elaphe taeniura, Bungarus multicinctus and Dinodon rufozonatum). The total prevalence of Kalicephalus in snakes in Hunan Province was 39.7%. The most common species was K. indicus, with the highest prevalence 72.8%, followed by K. bungari (24.0%). The prevalence of K. brachycephalus was 0.9%. This is the first report on the prevalence of Kalicephalus species in snakes in China, and the findings have important implications for the control of Kalicephalus infections in snakes in China.

Dynamical electron diffraction simulation for non-orthogonal crystal system by a revised real space method.

In the transmission electron microscopy, a revised real space (RRS) method has been confirmed to be a more accurate dynamical electron diffraction simulation method for low-energy electron diffraction than the conventional multislice method (CMS). However, the RRS method can be only used to calculate the dynamical electron diffraction of orthogonal crystal system. In this work, the expression of the RRS method for non-orthogonal crystal system is derived. By taking Na2 Ti3 O7 and Si as examples, the correctness of the derived RRS formula for non-orthogonal crystal system is confirmed by testing the coincidence of numerical results of both sides of Schrödinger equation; moreover, the difference between the RRS method and the CMS for non-orthogonal crystal system is compared at the accelerating voltage range from 40 to 10 kV. Our results show that the CMS method is almost the same as the RRS method for the accelerating voltage above 40 kV. However, when the accelerating voltage is further lowered to 20 kV or below, the CMS method introduces significant errors, not only for the higher-order Laue zone diffractions, but also for zero-order Laue zone. These indicate that the RRS method for non-orthogonal crystal system is necessary to be used for more accurate dynamical simulation when the accelerating voltage is low. Furthermore, the reason for the increase of differences between those diffraction patterns calculated by the RRS method and the CMS method with the decrease of the accelerating voltage is discussed.

Investigation on formaldehyde release from preservatives in cosmetics.

OBJECTIVE: To understand formaldehyde residue in cosmetics, an investigation on formaldehyde release from eight preservatives (methenamine - MA, paraformaldehyde - PF, poly(p-toluenesulfonamide-co-formaldehyde) -PTSAF, quaternium-15 - QU, imidazolidinyl urea - IU, diazolidinyl urea - DU, dimethyloldimethyl hydantoin - DMDM and bronopol - BP) under various conditions was performed. METHODS: The concentration of released formaldehyde was determined by high-performance liquid chromatography with photodiode array detection after derivatization with 2,4-dinitrophenylhydrazine. RESULTS: The amounts of formaldehyde release were in the order of PF > DU > DMDM ≈ QU ≈ IU > MA > BP > PTSAF. The releasing amounts of formaldehyde were the highest in the presence of aqueous matrices for the releasers except QU and IU, and the releasing effect was also relative to pH. More formaldehyde was released with longer storage time and higher temperature. Furthermore, all preservatives in cosmetic matrices released fewer amounts of formaldehyde than in pure aqueous or organic matrices, and the formaldehyde-releasing amounts were also cosmetic specific. CONCLUSION: Formaldehyde release was dependent on the matrix, pH, time and mainly temperature, and the releasing effect was also cosmetic specific.