Transformation of PMMA from sunlight-blocking to sunlight-activated coupled with DNH photocatalytic platform for oxidative coupling of amines and generation/regeneration of LDC/NADH.

The photocatalytic oxidation and generation/regeneration of amines to imines and leucodopaminechrome (LDC)/NADH are subjects of intense interest in contemporary research. Imines serve as crucial intermediates for the synthesis of solar fuels, fine chemicals, agricultural chemicals, and pharmaceuticals. While significant progress has been made in developing efficient processes for the oxidation and generation/regeneration of secondary amines, the oxidation of primary amines has received comparatively less attention until recently. This discrepancy can be attributed to the high reactivity of imines generated from primary amines, which are prone to dehydrogenation into nitriles. In this study, we present the synthesis and characterization of a novel polymer-based photocatalyst, denoted as PMMA-DNH, designed for solar light-harvesting applications. PMMA-DNH incorporates the light-harvesting molecule dinitrophenyl hydrazine (DNH) at varying concentrations (5%, 10%, 20%, 30%, and 40%). Leveraging its high molar extinction coefficient and slow charge recombination, the 30% DNH-incorporated PMMA photocatalyst proves to be particularly efficient. This photocatalytic system demonstrates exceptional yields (96.5%) in imine production and high generation/regeneration rates for LDC/NADH (65.27%/78.77%). The research presented herein emphasizes the development and application of a newly engineered polymer-based photocatalyst, which holds significant promise for direct solar-assisted chemical synthesis in diverse commercial applications.

Is colorectal endoscopic submucosal dissection safe and effective for 15-19-mm tumors?

PURPOSE: The outcomes of colorectal endoscopic submucosal dissection (ESD) in 15-19-mm tumors are unclear. This study compared the effectiveness and safety of colorectal ESD for 15-19-mm tumors and tumors exceeding that size. METHODS: From August 2018 to December 2020, 213 cases of colorectal tumors removed by colorectal ESD at a tertiary hospital were enrolled in this study. The cases were divided into two groups according to the pathologically measured size of the resected lesion: an intermediate group (15-19 mm, n = 62) and a large group (≥ 20 mm, n = 151). The en bloc resection rate, complete resection rate, and complications were investigated retrospectively. RESULTS: The en bloc resection rate was significantly higher in the intermediate than large group (100% vs. 94%, p = 0.049), and the mean total procedure time was shorter in the intermediate than large group (29.2 [Formula: see text] 12.6 vs. 48.4 [Formula: see text] 28.8 min, p < 0.001). However, the mean procedure speed was significantly lower in the intermediate than large group (0.25 [Formula: see text] 0.10 vs. 0.28 [Formula: see text] 0.11 cm2/min, p = 0.031). The complete resection rate, post-procedural bleeding, and perforation rate were not significantly different between the two groups. In multivariate analyses, the total procedure time and mean procedure speed were significantly associated with lesion size. CONCLUSION: Colorectal ESD of 15-19-mm lesions is effective, and has a shorter procedure time and higher en bloc resection rate than the same procedure for larger lesions.

Mechanical and Pore Properties of Concrete Using Basalt-Based Recycled Aggregates According to Mixture Conditions.

This study investigated recycled aggregates of Jeju Island-where porous basalt exists as a natural aggregate-and is a study aimed at verifying the applicability of the basalt-based recycled aggregate in the field. To this end, the application properties of concrete were analyzed using the quality improvement of the recycled aggregate (PRA), the type of fine aggregate received in the region, and the cement content as variables. In an experiment using concrete in which 50% of the PRA was replaced with basalt (BA), the air content of the fresh concrete decreased due to the increasing solid content of the aggregate when PRA and fine aggregates (with an even particle size distribution) were used. Regarding the properties of the hardened concrete, when the PRA and fine aggregate (with a high fineness modulus) were used, the compressive strength was 33.6 MPa and the modulus of elasticity was 23.1 GPa, which are higher than those of the BA specimen. The resistance to carbonation increased due to the improved quality of the PRA specimen. Pores that are 0.3 mm in size or larger decreased when the PRA and fine aggregates of even particle sizes were used. This form of pore reduction was found to have a direct correlation with the improvement of mechanical properties.

Study on Mechanical Properties of Concrete Using Basalt-Based Recycled Aggregate and Varying Curing Conditions.

To replace porous basalt, the mechanical properties of concrete with recycled resources and durability improvement were analyzed in this study. The analysis was based on the quality improvement of recycled aggregate, use of fly ash, and changes in curing conditions. Basalt aggregate (BA) with a 3% water absorption, raw recycled aggregate and basalt (RRA), and improved recycled aggregate and basalt (PRA) were the main experimental variables. As PRA was applied to concrete, the compressive strength was lower than that of the specimen comprising BA in the normal strength region, but the modulus of elasticity (22.9 GPa) was equivalent or higher. The initial drying shrinkage increased because of the use of basalt-based recycled aggregate (B-RA). The drying shrinkage of PRA was similar to that of BA with an average difference of <7% as the age increased. The specimens subjected to steam curing exhibited the lowest drying shrinkage. These results showed that pores in the old paste of recycled aggregate increased freeze−thaw resistance because of the increase in the spacing factor. Although the PRA did not satisfy the quality criteria, the efficient use of recycled aggregate achieved an equivalent or higher performance than that of concrete comprising BA and improved durability.

Shoe Dermatitis.

Shoe dermatitis is a type of contact dermatitis precipitated by allergens or irritants found in shoes. Potassium dichromate, commonly used in leather processing, is one of the most prevalent agents responsible for shoe dermatitis; however, it is not the only one. Shoe dermatitis caused by an allergen or an irritant may affect a person of any age, sex, or ethnicity. Numerous treatments exist for shoe dermatitis, the most simple yet important being avoidance of causative agents. Pharmaceutical agents commonly used are emollients, humectants, and topical corticosteroids. In more severe cases, topical calcineurin inhibitors and phototherapy may be used.

Mechanical Properties of Basalt-Based Recycled Aggregate Concrete for Jeju Island.

Recycled aggregate is essential to protect Jeju Island's natural environment, but waste concrete, including porous basalt, is a factor that lowers the quality of recycled aggregate. Therefore, an experiment was conducted to analyze the properties of concrete application of basalt-based recycled aggregate (B-RA) through quality improvement. The absorption of the B-RA ranged from 3-5%; restricting its absorption to less than 3% was challenging owing to its porosity and irregular shape. However, the increase in the solid volume percentage of the concrete when replacing 25 or 50% of fresh basalt aggregate with recycled basalt aggregate improved the mechanical performance of the concrete, especially at 25%, for which a compressive strength of 55.9 MPa and modulus of elasticity of 25.9 GPa exceeded those of concrete with fresh basalt aggregate. Moreover, increasing the replacement ratio of the fresh basalt with recycled aggregate reduced the slump and decreased the air content, consequently increasing the concrete drying shrinkage. However, the replacement of fresh basalt aggregate with recycled basalt aggregate unaltered the mechanical performance of the concrete. The results indicate that efficient use of recycled aggregates can yield superior performance to that of fresh basalt, irrespective of aggregate quality.

The Role of Plant Extracts in Alleviating Particulate Matter-induced Inflammation in Barrier-interrupted Skin / 대한피부과학회지

Background@#The adverse effects of particulate matter (PM) on the skin have been concerning recently. @*Objective@#We investigated PM induced inflammation on barrier-interrupted skin and relieving effects of plant extracts on PM-induced skin irritation. @*Methods@#A total of 20 participants were enrolled for the induction of skin irritation. Sodium lauryl sulfate (SLS) patch was affixed to the forearm for 24 hours. After patch removal, total suspended particulates (TSPs) were applied. After inducing skin irritation using SLS and TSP, cream containing 0.1% mixture of plant extracts (Citrus sunki, Sceptridium ternatum (Botrychium ternatum), and Korthalsella japonica) was applied. The a* value, erythema index (EI), and transepidermal water loss (TEWL) were measured. @*Results@#The a* value was significantly higher at the site where TSPs were applied than that at the site where TSPs were not applied at 1 and 2 days after SLS patch removal. The a* value, EI, and TEWL were significantly low in the cream-applied area 7 days after the introduction of the SLS patch and TSPs. @*Conclusion@#PM induced skin irritation in a previously disrupted skin barrier. Topical application of plant extracts alleviated skin irritation symptoms caused by dust exposure.

The Role of Plant Extracts in Alleviating Particulate Matter-induced Inflammation in Barrier-interrupted Skin / 대한피부과학회지

Background@#The adverse effects of particulate matter (PM) on the skin have been concerning recently. @*Objective@#We investigated PM induced inflammation on barrier-interrupted skin and relieving effects of plant extracts on PM-induced skin irritation. @*Methods@#A total of 20 participants were enrolled for the induction of skin irritation. Sodium lauryl sulfate (SLS) patch was affixed to the forearm for 24 hours. After patch removal, total suspended particulates (TSPs) were applied. After inducing skin irritation using SLS and TSP, cream containing 0.1% mixture of plant extracts (Citrus sunki, Sceptridium ternatum (Botrychium ternatum), and Korthalsella japonica) was applied. The a* value, erythema index (EI), and transepidermal water loss (TEWL) were measured. @*Results@#The a* value was significantly higher at the site where TSPs were applied than that at the site where TSPs were not applied at 1 and 2 days after SLS patch removal. The a* value, EI, and TEWL were significantly low in the cream-applied area 7 days after the introduction of the SLS patch and TSPs. @*Conclusion@#PM induced skin irritation in a previously disrupted skin barrier. Topical application of plant extracts alleviated skin irritation symptoms caused by dust exposure.

A study of skin characteristics with long-term sleep restriction in Korean women in their 40s.

BACKGROUND: Previous studies have demonstrated increased pore size and darkening skin color with total sleep deprivation. There are many studies of skin characteristics with short-term sleep restriction, but there are few studies on skin characteristics when sleep is restricted more than three consecutive days. This study evaluated skin changes with sleep limited to 4 hours per night for six nights. MATERIALS AND METHODS: The study included 32 Korean women in their 40s. Skin hydration, desquamation, barrier recovery, texture, gloss, transparency, elasticity, crow's feet, frown lines, and color were measured. Individual sleep time was monitored by smartwatches. Subjects slept 8 hours per night for six nights in week one and 4 hours per night for six nights in week two. RESULTS: Skin hydration was significantly reduced after 1 day of sleep deprivation, and it continued to decrease. Skin gloss, desquamation, transparency, elasticity, and wrinkles were significantly aggravated after 1 day of sleep deprivation. Skin texture was significantly aggravated on the fourth day of sleep restriction. Elasticity was most affected by reduced sleep, with a standardized coefficient of -.320, indicating a significant decrease over time as compared to other characteristics. CONCLUSION: Skin hydration was gradually decreased with sleep restriction. Skin texture did not change after only 1 day of sleep restriction. It is a new finding that elasticity decreases more than other skin characteristics with prolonged sleep restriction.

Genome-Wide Transcriptome Analysis of Rice Seedlings after Seed Dressing with Paenibacillus yonginensis DCY84T and Silicon.

Plant-growth-promoting bacteria (PGPB) are beneficial microorganisms that can also protect against disease and environmental stress. Silicon (Si) is the second most abundant element in soil, and is known to increase plant growth, grain yield, resistance to biotic stress, and tolerance to abiotic stress. Combined treatment of PGPB and Si has been shown to further enhance plant growth and crop yield. To determine the global effects of the PGPB and Si on rice growth, we compared rice plants treated with Paenibacillus yonginensis DCY84T (DCY84T) and Si with untreated rice. To identify the genes that respond to DCY84T+Si treatment in rice, we performed an RNA-Seq transcriptome analysis by sampling treated and untreated roots on a weekly basis for three weeks. Overall, 576 genes were upregulated, and 394 genes were downregulated in treated roots, using threshold fold-changes of at least 2 (log2) and p-values < 0.05. Gene ontology analysis showed that phenylpropanoids and the L-phenylalanine metabolic process were prominent in the upregulated genes. In a metabolic overview analysis using the MapMan toolkit, pathways involving phenylpropanoids and ethylene were strongly associated with upregulated genes. The functions of seven upregulated genes were identified as being associated with drought stress through a literature search, and a stress experiment confirmed that plants treated with DCY84T+Si exhibited greater drought tolerance than the untreated control plants. Furthermore, the predicted protein-protein interaction network analysis associated with DCY84T+ Si suggests mechanisms underlying growth promotion and stress tolerance.

Two cases of primary cutaneous nocardiosis caused by intralesional injection.

Nocardiosis is a rare localized or systemic suppurative disease caused by the actinomycete Nocardia species. The respiratory tract is the most common site of infection, but primary cutaneous nocardiosis can also be induced by direct inoculation. Nocardiosis is usually reported in immunocompromised patients, such as those with human immunodeficiency virus (HIV) infection, chronic obstructive pulmonary disease, autoimmune diseases, cancer, or in those who have had organ transplantation or corticosteroid administration. However, it can also affect individuals with no serious underlying condition. We reported two cases of primary cutaneous nocardiosis in immunocompetent patients after intralesional injection of steroid.

Efficacy and safety of a novel, soluble microneedle patch for the improvement of facial wrinkle.

BACKGROUND: Various kinds of functional cosmetics are on the market, although there are a variety of opinions concerning the actual effect. Transdermal microneedle patch has been introduced as a newly developed device for drug delivery through the skin. OBJECTIVE: This study was conducted to verify the face skin improvement effect and safety of a novel cosmetic microneedle patch. METHODS: A total of 84 Korean females finished this prospective clinical trial. The subjects were divided into 3 groups: (1) soluble hyaluronic acid (HA) microneedle patch alone, (2) soluble HA microneedle patch plus adenosine wrinkle cream, and (3) adenosine wrinkle cream alone. The treatments were applied to the crow's feet and nasolabial fold wrinkle for 12 weeks. The test areas were measured before treatment and at 4, 8, and 12 weeks after use of the test product. At the completion of the testing period of the trial, the global assessment of efficacy and product preferences were surveyed from the subjects. RESULTS: Combination treatment with wrinkle cream and microneedle patch significantly improved Merz scale for crow's feet and nasolabial folds, compared to the sole application of wrinkle cream or patch. Measurement on the crow's feet showed an overall improvement in all 3 groups, yielding no significant differences among the groups. No serious adverse effects were observed during the follow-up period. CONCLUSION: Combination application of a soluble microneedle patch and wrinkle cream was an effective treatment in improving facial wrinkles, thus enhancing skin rejuvenation.

Nonlinear micro-CT based FE modeling of trabecular bone-Sensitivity of apparent response to tissue constitutive law and bone volume fraction.

In this study, the sensitivity of the apparent response of trabecular bone to different constitutive models at the tissue level was investigated using finite element (FE) modeling based on micro-computed tomography (micro-CT). Trabecular bone specimens from porcine femurs were loaded under a uniaxial compression experimentally and computationally. The apparent behaviors computed using von Mises, Drucker-Prager, and Cast Iron plasticity models were compared. Secondly, the effect of bone volume fraction was studied by changing the bone volume fraction of a trabecular bone sample while keeping the same basic architecture. Also, constitutive models' parameters of the tissue were calibrated for porcine bone, and the effects of different parameters on resulting apparent response were investigated through a parametric study. The calibrated effective tissue elastic modulus of porcine trabecular bone was 10±1.2 GPa, which is in the lower range of modulus values reported in the literature for human and bovine trabecular bones (4-23.8 GPa). It was also observed that, unlike elastic modulus, yield properties of tissue could not be uniquely calibrated by fitting an apparent response from simulations to experiments under a uniaxial compression. Our results demonstrated that using these 3 tissue constitutive models had only a slight effect on the apparent response. As expected, there was a significant change in the apparent response with varying bone volume fraction. Also, both apparent modulus and maximum stress had a linear relation with bone volume fraction.

Correlations of leukemia inhibitory factor and macrophage migration inhibitory factor with endometrial carcinoma.

OBJECTIVE: To investigate the correlations of leukemia inhibitory factor (LIF) and macrophage migration inhibitory factor (MIF) with endometrial carcinoma. MATERIALS AND METHODS: The study included 113 endometrial specimens from the Fourth Affiliated Hospital of Harbin Medical University, collected from May 2006 to October 2008, classified into normal endometrium, simple hyperplasia, complex hyperplasia, atypical hyperplasia, and endometrial carcinoma. The LIF and MIF expression of all 113 specimens was detected with immunohistochemistrical (IHC) method. RESULTS: The MIF expression in hyperplastic endometrium and endometrial carcinoma increased significantly as compared with that in normal endometrium (p < 0.05 and p < 0.001, respectively), and its expression in endometrial carcinoma was also remarkably higher than that in hyperplastic endometrium (p < 0.001). The expressions of LIF in atypical hyperplasia and endometrial carcinoma were also significantly higher than that in the normal endometrium (p < 0.05), but it is not obviously higher in simple hyperplasia and complex hyperplasia than in the normal endometrium (p > 0.05). Furthermore, the expression of LIF showed no statistical difference between hyperplastic endometrium and endometrial carcinoma. CONCLUSION: It could be speculated that MIF may be correlated with the occurrence of endometrial carcinoma. However, whether LIF also has a correlation with the occurrence of endometrial carcinoma still cannot be presumed.

The relationship between disease activity measured by the BASDAI and psychological status, stressful life events, and sleep quality in ankylosing spondylitis.

Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) is a standard instrument regularly used to assess disease activity of patients with ankylosing spondylitis (AS). However, the well-being of a patient is also affected by impairment of function as well as psychological status and other factors. The objective of this study was to evaluate if psychological status, stressful life events, and sleep quality contribute significantly to BASDAI. Six hundred eighty-three AS patients satisfying the Modified New York Criteria for AS were recruited from the rheumatology clinics of seven hospitals in China. Patients with other concomitant disorders were excluded. Participants were requested to complete a set of clinical examinations and the following questionnaires: Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), Zung Self-Rating Anxiety Scale (SAS), Zung Self-Rating Depression Scale (SDS), Pittsburgh Sleep Quality Index Questionnaire (PSQI), Health Assessment Questionnaire for Spondyloarthropathies (HAQ-S), and Social Readjustment Rating Scale (SRRS). Spearman correlation analysis showed that BASDAI was highly associated with degree and duration of morning stiffness, overall pain, nocturnal back pain, overall back pain, anxiety, and BASFI (all P < 0.001), but were not associated with education, HAQ-S, and sleep medication in PSQI (P > 0.05). Multiple stepwise regression analysis indicated that overall pain was the maximal statistical contribution in predicting disease activity (standardized coefficient, 0.335). In hierarchic multiple regression analysis, psychological variables added an only additional 2.7% to the overall R(2) beyond that accounted for by demographic and medical variables, resulting in a final R(2) of 53.5%. Although BASDAI is a very good measurement of pain and stiffness and to a certain extent effect of functional impairment in AS, it barely takes into account psychological status, stress life events, and sleep quality These factors should be evaluated by other modalities.

Epidemiological comparison of clinical manifestations according to HLA-B*27 carrier status of Chinese ankylosing spondylitis patients.

The aim of the study was to investigate and compare the clinical manifestations between HLA-B27(+) and HLA-B27(-) ankylosing spondylitis (AS) patients in order to obtain knowledge of the impact of HLA-B27 status on AS, and to inform clinical treatment. A nationwide epidemiological investigation was performed from November 2008 to October 2010. The demographic data and clinical characteristics, and the status of HLA-B27 were collected using questionnaires and laboratory assay, respectively. A total of 2144 patients (78.5% males and 78.4% HLA-B27(+) AS patients) participated in this study. The percentages of males, patients with family history, and involvement of lumbar spine, thoracic spine and hip joints, were observed to be significantly higher in the HLA-B27(+) AS patients than in their HLA-B27(-) AS peers.

Cryoprotection of fibroblasts by carboxylated poly-L-lysine upon repeated freeze/thaw cycles.

The cryoprotection of carboxylated h-poly-L-lysine (COOH-PLL) was investigated on fibroblasts [L-929 cells and human dermal fibroblasts (HDFs)] during multiple freeze/thaw cycles. COOH-PLL was not toxic to two fibroblast cell types even at 25% (w/v) concentration, whereas dimethylsulphoxide (DMSO) was highly toxic over 3.13% (v/v). When L-929 cells were subjected to 5 freeze/thaw cycles, the media containing 7.5% (w/v) COOH-PLL maintained cell morphology and significantly suppressed growth inhibition as well as cell detachment (P < 0.05). The result was comparable to the media containing 10% (v/v) DMSO. For HDFs, COOH-PLL could effectively retain cell viability and proliferation against 3 freeze/thaw cycles. Cell viability of HDFs was decreased after 5 freeze/thaw cycles, but COOH-PLL exerted better cryoprotection. The cell type might account for the difference in the observations. The data demonstrated that COOH-PLL is a good cryoprotectant for mammalian cells against repeated freeze/thaw cycles, and may be used for cell preservation in fields of cell transplantation, tissue engineering and regenerative medicine.

Higher risk of uveitis and dactylitis and older age of onset among ankylosing spondylitis patients with HLA-B*2705 than patients with HLA-B*2704 in the Chinese population.

Human leukocyte antigen (HLA)-B27 is closely associated with ankylosing spondylitis (AS). However, the exact correlation between HLA-B27 subtypes and AS manifestations remains unknown. This study aimed to investigate the correlation between HLA-B27 polymorphism and the clinical features of AS. This study included 846 patients with AS and 959 healthy controls. Direct sequencing was used to identify the HLA-B27 genotype. Clinical parameters, including age, age of onset, family history, low back pain, peripheral arthritis, hip joint involvement, dactylitis, uveitis, and sex ratio, were compared among patients with various HLA-B27 subtypes. In total, 741 AS patients (87.6%) and 39 healthy controls (4%) were HLA-B27-positive. The most prevalent subtypes were HLA-B*2704 (88%) and HLA-B*2705 (10.1%) in patients with AS. Compared with HLA-B*2704-positive patients, HLA-B*2705-positive patients demonstrated a significant increase in the incidence of uveitis (16% vs 6.13%, P = 0.002) and dactylitis (9.3% vs 3.8%, P = 0.028) and they had an older age of onset (22.9 ± 8.0 vs 20.7 ± 6.7 years, P = 0.028). Binary logistic regression analysis revealed that presence of uveitis was significantly associated with HLA-B*2705 (P = 0.008; odds ratio, 2.63; 95% confidence interval, 1.283-5.393). There were no significant differences in family history, low back pain, peripheral arthritis, or hip joint involvement among HLA-B27 subtypes. Specific HLA-B27 subtypes were positively associated with particular clinical features of AS. AS patients with HLA-B*2705 demonstrated an older age of onset and had a higher risk of uveitis and dactylitis than did AS patients with HLA-B*2704.

The Value of Preoperative Magnetic Resonance Cholangiopancreatography (MRCP) in Patients Who will be Performed Laparoscopic Cholecystectomy

PURPOSE: The aim of this study is to evaluate the value of preoperative MRCP prior to laparoscopic cholecystectomy by analysis of postoperative outcomes. METHODS: Between 2009.12~2010.12, 283 patients underwent laparoscopic cholecystectomy for treatment of benign biliary disease. Among these patients, 125 underwent preoperative MRCP and were classified as the MRCP group. The remaining 158 patients who did not undergo MRCP were classified as the non MRCP group. We compared perioperative data, including the rate of bile duct injury, operative complication, conversion rate, hospital stay, and hospital cost between the two groups. In addition, we analyzed preoperative MRCP findings, including common bile duct (CBD) stones and bile duct anomaly. RESULTS: Findings on pre-operative MRCP scan revealed silent CBD stones in five patients (4.0%) and bile duct anomalies were identified in 17 patients (13.6%). Three cases of bile duct injury occurred in the non MRCP group, whereas, no bile duct injury occurred in the MRCP group. No significant statistical difference in postoperative complication was observed in either group. Mean duration of operation was 50.5 (+/-30.4) minutes in the MRCP group, and 52.2 (+/-29.9) minutes in the non MRCP group (p=0.630). Post operative hospital stay was 2.1 (+/-1.4) days (mean) in the MRCP group, and 2.5 (+/-2.5) days in the non MRCP group. No statistical difference was observed between the two groups (p=0.110). CONCLUSION: MRCP may be useful for evaluation of bile duct anomaly and identification of hidden bile duct stones. However, this modality did not show statistical benefits for postoperative outcomes in patients who underwent laparoscopic cholecystectomy.

Influence of operation conditions and additives on the development of producer gas and tar reduction in air gasification of construction woody wastes using a two-stage gasifier.

Air gasification was conducted with fractions of construction woody wastes in a two-stage gasifier, consisting of a fluidized bed zone and a tar cracking zone. The aim of this work is to investigate the influence of reaction conditions and additives on the composition of producer gas and tar content in producer gas. A producer gas obtained with activated carbon of 540 g at an ER of 0.26 was mainly composed of H(2) (25 vol.%), CO (22 vol.%) and CH(4) (5 vol.%). Regarding tar removal efficiency, activated carbon was better than olivine. The tar removal rate with virgin activated carbon reached up to 80%. The reuse of spent activated carbon caused an efficiency loss in tar removal to some extent. Overall, it seems that the strong need for intensive downstream tar removal measurements can be removed with the use of a two-stage gasifier and the application of activated carbon.