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Liangshan Prefecture is one of the three major forest areas in Sichuan Province and one of the three major disaster areas of forest fire. We measured the physicochemical properties and combustion performances of different organs (leaves and branches) of 15 main economic tree species in Liangshan, and analyzed the bioecology characteristics, silviculture characteristics and value characteristics of different tree species. We investigated the fire resistance of different tree species to screen out fire-resistant species suitable for economic forest development in Liangshan Prefecture, and improve the biological fire prevention ability. The seven physicochemical properties and combustion performances indices of 15 tree species showed significant differences. Except for crude ash and lignin, the weights of moisture content, caloric value, ignition point, crude fat, and crude fibre of leaves were higher than those of branches. Crude fibre index of leaves (9.6%) and the crude ash index of branches (9.9%) were the highest weight indices of the two organs, respectively. Based on the fire resistance, we divided all the species into three classes, i.e ., class Ⅰ (excellent fire-resistance trees) Juglans regia and Morus alba ; class Ⅱ (better fire-resistant trees) Sapium sebiferum , Mangifera indica , Phyllanthus emblica , Eriobotrya japonica , Ligustrum lucidum , Castanea mollissima , and Punica granatum ; class Ⅲ (poor fire-resistant trees) Pinus armandii , Illicium simonsii , Morella rubra , Sapindus mukorossi , Olea europaea and Camellia oleifera . J. regia and M. alba had fireproof solid performance and could be used as the preferred species for fireproof economic forest in Liangshan region. It was suggested that to use class Ⅰ to Ⅱ fire-resistant tree species built the main fireproof isolated forest belt, and pay attention to fire prevention after planting class Ⅲ tree species in a large area.

While sludge bulking often occurring in activated sludge processes generally leads to serious membrane fouling in membrane bioreactors (MBR), the underlying causes are still unclear. In this study, fouling behaviors of a MBR operated at stages of normal and sludge bulking were compared, and the fouling mechanisms of the different behaviors were explored. It was found that, the MBR could be stably operated in normal stage without membrane cleaning for about 60 days, whereas, daily membrane cleaning had to be carried out when operated in sludge bulking stage. The bulking sludge possessed a rather high specific filtration resistance (SFR) of about 1.36×10 14 m·kg -1 , which is over 5.33 times than that of the normal sludge. A series of characterizations demonstrated that the bulking sludge had rather lower dewaterability, smaller particle size, higher fractal dimension, higher viscosity, abundant filamentous bacteria and different functional groups of extracellular polymer sustains (EPS). It was suggested that microbial community transition was responsible for the occurrence of sludge bulking, further affecting membrane fouling. Based on these characterizations, it was reported that adhesion propensity (indicated by the thermodynamic interaction) of the bulking sludge to the membrane surface is about 3.6 times than that of the normal sludge. It was proposed that, extra force should be provided to offset a chemical potential gap caused by foulant layer structure transition during sludge bulking in order to sustain filtration of the bulking sludge, resulting in extremely high SFR. This study offered deep thermodynamic mechanisms of MBR fouling during occurrence of sludge bulking., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Eight previously undescribed lanostane triterpenoids, ganodeweberiols A ∼ H (1-8), together with eighteen known compounds (9-26), were isolated from the fruiting bodies of Ganoderma weberianum. The structures and absolute configurations of the new compounds were determined by extensive spectroscopic analysis, as well as NMR chemical shifts and electronic circular dichroism (ECD) calculations. Compounds 2, 7, 12, and 14 showed significant α-glucosidase inhibitory activity with IC 50 values ranging from 35.3 μM ∼ 223.4 μM compared to the positive control acarbose (IC 50 , 304.6 μM). Kinetic study indicated that the most potent compound 12 was a mixed type inhibitor for α-glucosidase. Molecular docking simulation revealed the interactions of 12 with α-glucosidase. Additionally, Compounds 3 and 6 inhibited glucagon-induced hepatic glucose production in HepG2 cells with EC 50 values of 42.0 and 85.9 μM, respectively. Further study revealed that compounds 3 and 6 inhibited hepatic glucose production by suppression glucagon-induced cAMP accumulation. Moreover, compounds 3 and 26 were active against HeLa cell line with IC 50 values of 17.0 and 6.8 μM, respectively., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Based on panel data from 30 provinces in China from 2008 to 2017, this paper constructs a quantile regression econometric model to analyze whether China's environmental regulation has an impact on export trade and to verify whether the Porter hypothesis has been valid in China in recent years. The results show that in the short term, environmental regulations have a restraining effect on export trade, while in the long run, due to the existence of innovation efficiency, environmental regulations will change from having a restraining effect to a promoting effect on export trade. Strict environmental regulations will reduce the production cost of Chinese products, further improve the export competitiveness of Chinese enterprises, and promote export trade. The empirical results verify the conclusion that the Porter hypothesis is confirmed in China. The following three suggestions are proposed for China's exports to promote the win-win of China's green development and export trade: promote the realization of international and domestic double circulation, avoid becoming "pollution shelters" and support technological innovation in environmental protection industries., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objectives: The purpose of this study was to reveal the correlation between superior mesenteric artery (SMA) blood flow in the first 12 hours of life and the risk of necrotizing enterocolitis (NEC) in preterm neonates., Methods: We conducted a prospective study. There were 104 preterm neonates included in our study. The SMA blood flow of each neonate was measured during the first 12 hours of life if the hemodynamic situation was stable. The results of Doppler ultrasound were confidential to the neonatologists and nurses. All of the demographics, comorbidities, and outcomes were recorded and analyzed., Results: Among all of the demographics and comorbidities, the gestational age was related to the measurements of SMA blood flow. We conducted a single-factor analysis of the occurrence of NEC, including the peak systolic velocity (PSV), end-diastolic velocity, time-averaged mean velocity, differential velocity (DV), resistive index, and pulsatility index. A higher PSV (median [interquartile range], 54.165 [42.423-68.463] versus 42.195 [34.278-48.553] cm/s; P = .027) and DV (median [interquartile range], 47.445 [35.010-60.043] versus 32.565 [27.545-39.073] cm/s; P = .020) were significantly related to the risk of NEC. In the logistic analysis including gestational age, PSV, and DV, NEC was significantly associated with gestational age (odds ratio [95% confidence interval], 0.644 [0.456-0.908]; P = .012) and DV (odds ratio [95% confidence interval], 1.144 [1.058-1.237]; P < .01). The area under the receiver operating characteristic curve for the DV was 0.768, with sensitivity 0.875 and specificity 0.604. The cutoff value of the DV was 34.835 cm/s., Conclusions: From this single-center study, we can see the promising value of Doppler ultrasound for the prediction of NEC, but further research is needed., (© 2019 by the American Institute of Ultrasound in Medicine.)

Retinitis pigmentosa (RP) represents a clinically and genetically heterogeneous disease characterized by progressive photoreceptor loss. In recent years, research has been rarely made in blood flow affected in RP. The specific mechanism of blood flow affected in RP is not completely clear. A number of studies indicated that the decreased blood flow was related to RP. According to clinical observation and treatment experience, Chinese medicine considered that blood stasis runs throughout the RP disease progression, and the blood stasis corresponding to Chinese herbal medicine has a positive effect on the clinical treatment of RP. Therefore, we proposed that the decreased blood flow may participate in the lesion. In this article, we will review the findings on the decreased blood flow affected in RP from the perspective of modern medicine and Chinese medicine.

Aim: To evaluate the long-term effectiveness and late toxicities of paclitaxel (PTX) plus cisplatin (DDP) with concurrent radiotherapy for locally advanced esophageal squamous cancer., Methods: Between 2008 and 2011, 76 patients were enrolled in a phase II study on the treatment of loco-regionally advanced esophageal cancer with radiotherapy (68.4 Gy/44 fractions or 61.2 Gy/34 fractions) combined with 4-cycle chemotherapy consisting of DDP (25 mg/m 2 per day for 3 d) and PTX (175 mg/m 2 for 3 h). The primary endpoints were overall survival and progression-free survival, and the secondary endpoints were toxicity and the treatment failure pattern., Results: A total of 76 patients were enrolled in this study, of whom 63.2% finished the whole regimen. The 5-year survival rates for the per-protocol population and intent-to-treat population were 25.4% and 26.4%, respectively, and the median survival rates were 23.7 mo and 28.5 mo, respectively. Grade 3 or 4 late toxicity was observed in only one patient (heart failure). In log-rank analysis, the pretreatment stage (stage II + III: 36.1 mo vs stage IV: 14.9 mo) and the completed cycle (1-3 cycles: 16.1 mo vs 4 cycles: 35.5 mo) were significant prognostic factors ( P = 0.037 < 0.05 and P = 0.013 < 0.05)., Conclusion: Radiotherapy combined with chemotherapy consisting of PTX and DDP is a safe and effective definitive treatment for loco-regionally advanced esophageal squamous cancer., Competing Interests: Conflict-of-interest statement: The authors of this manuscript have no conflicts of interest to disclose.

Objective: To analyze the status and characteristics of dental manpower in the center for disease controls (CDC) in Sichuan Province and to provide more evidence for strengthening the oral healthcare workforce in the CDC system., Methods: A mass survey on dental manpower was made in CDCs in Sichuan Province through questionnaire investigation. Data were collected and entered with the Epidemiological Dynamic Data Collection (EDDC) platform and analyzed with SPSS 13.0 software., Results: Sichuan Province had 0.15 hospitals providing oral health services and 0.38 dentists on average per 10,000 people. About 65.53% (135/206) of the CDCs had one department responsible for the oral health service. However, oral health care personnel comprised only 2.23% (237/10,624) of the personnel of the whole CDC system. About 64.67% (119/184) of county CDCs and 47.62% (10/21) of city CDCs knew well the dental health status of local residents. Less than 5% of the CDCs used the data and assisted in the policy making of public health administrators., Conclusion: The dental care personal deficit exists in the CDC system in Sichuan Province. The distribution and composition of dental manpower are not reasonable. The oral health service ability of CDCs in Sichuan Province should be strengthened and improved.

Background: Adenovirus is one of the most common causes of viral acute respiratory infections. To identify the types of human adenoviruses (HAdVs) causing respiratory illness in Beijing, a sentinel surveillance project on the viral aetiology of acute respiratory infection was initiated in 2011., Principal Findings: Through the surveillance project, 4617 cases of respiratory infections were identified during 2011-2013. Throat swabs (pharynx and tonsil secretions) were collected from all the patients, and 15 different respiratory viruses were screened by multiplex one-step PCR method. 45 were identified as adenovirus-positive from sporadic and outbreak cases of respiratory infection by a multiplex one-step RT-PCR method, and a total of 21 adenovirus isolates were obtained. Five HAdV types among three species, including HAdV-3 (species HAdV-B), HAdV-4 (species HAdV-E), HAdV-7 (species HAdV-B), HAdV-55 (species HAdV-B), and an undefined HAdV type (species HAdV-C) were identified. The comparison results of the penton base, hexon, and fiber gene sequences of the Beijing HAdV-3, HAdV-4, HAdV-7, and HAdV-55 strains in this study and those from the GenBank database indicated significant spatial and temporal conservation and stability of sequences within the genome; however, the phylogenetic relationship indicated that both strain BJ04 and strain BJ09 isolated in 2012 and 2013, respectively, may have recombined between HAdV-1 genome and HAdV-2 genome within species HAdV-C, indicating intraspecies recombination., Conclusions: This study confirmed that at least 5 HAdV types including HAdV-3, HAdV-4, HAdV-7, HAdV-55 and an undefined HAdV type were co-circulating and were the causative agents of respiratory tract infections in recent years in Beijing. HAdV-3, HAdV-4, HAdV-7, and HAdV-55 showed the apparent stability of the genomes, while intraspecies recombination was identified in strain BJ04 and BJ09. The recombinants carrying penton base gene of HAdV-1 as well as hexon and fiber genes of HAdV-2 might be a novel type of HAdV worthy of further study.

Multiple myeloma is a primary malignancy of bone marrow characterized by the clonal proliferation of plasma cells and production of monoclonal immunoglobulin. The disease occurs more frequently in males, with the average age at diagnosis being ∼60 years. The first manifestation of multiple myeloma is varied and depends on the sites and extent of involvement. The predominant clinical symptoms of multiple myeloma are associated with bone pain and renal dysfunction. Neoplastic cells usually produce large amounts of monoclonal immunoglobulin light or heavy chains that can be detected in serum or urine, while plasmacytoma may be identified on marrow biopsy. The present study reported on the case of a 69-year-old male patient presenting with a complaint of a painful lesion in the left maxilla. Physical examination, imaging, laboratory investigations and biopsy were conducted, confirming the diagnosis of multiple myeloma. The results obtained suggest that the dentist should address oral manifestations as first indications of multiple myeloma.

Background/aim: The purpose of this study was to evaluate the clinical significance of visualized area percentage assessment of cleansing score (AAC) and computed assessment of cleansing score (CAC) of these two small bowel cleanliness scores systems for capsule endoscopy (CE)., Materials and Methods: The reliability and consistency of the AAC and CAC scores were evaluated by comparing the scores by two examiners (one expert, one without any training in CE). Reliability was determined using the intraclass correlation coefficient (ICC) and consistency was determined using the kappa statistic., Results: The inter-observer agreement was excellent for both the AAC and CAC scores. For AAC, the ICC was 0.791 (95% confidence interval: 0.677-0.868), and for CAC the ICC was 1.000. Using 1.5 as the cutoff, there was no significant difference between AAC and CAC results by the expert examiner (kappa = 0.756, P = 0.000) or the non-expert examiner (kappa = 0.831, P = 0.000). Evaluation of small bowel cleanliness using AAC took 15-30 min, and evaluation using CAC took about 2-3 min. The overall adequacy assessment (OAA) using the AAC was not significantly different between the two examiners (χ2 = 0.586, P = 0.444). There were also no significant differences between the OAA using the AAC and the OAA using the CAC by the expert examiner (χ2 = 1.730, P = 0.188) or the non-expert examiner (χ2 = 1.124, P = 0.289)., Conclusion: Both of these scores for assessment of small bowel cleanliness can be useful in clinical practice, but the CAC is simpler to use.

We investigated the effects of intravenously administered bone marrow mesenchymal stem cells (BMSCs) on renal interstitial inflammation and fibrosis. In unilateral ureteral obstruction (UUO) rats, the CD4(+)CD25(+) regulatory T-cell (Treg) cell, macrophage population and some inflammation related cytokines were tested. In the BMSCs -treated rats, renal exhibited lower renal Masson scores, decreased macrophage infiltration and interferon gamma (IFNγ) expression, and increased forkhead transcription factor (Foxp3) and interleukin-10 (IL-10) expression. No significant differences in the CD4(+)CD25(+) Treg population and renal transforming growth factor-β1 (TGFβ1) expression were observed between BMSCs-treated group and control group (p>0.05). In conclusion, BMSCs infusion leads to an anti-inflammation response in the early stage of UUO which may related to paracine mechanism., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Objective: Long term glucocorticoid (prednisolone) treatment on human growth hormone (hGH) secretion in children and adolescents and to investigate the effectiveness and safety of the recombinant human growth hormone (rhGH) treatment., Methods: Twelve patients (age: 10.4∓1.2 years) who were treated in Peking Union Medical College Hospital from September 1999 to November 2009 were enrolled in this study. All of them had taken prednisolone with a dose of 0.5∓2.0 mg/(kg.d) for 6~18 months. Two different hGH stimulating tests was done and their growth and development was evaluated at regular intervals. Seven patients were given rhGH with a dose of 0.1 U/(kg.d) for 6~12 months to improve their growth and development after half a year of prednisolone withdrawal when their disease conditions were improved., Results: The growth speed of these 12 children decreased significantly during prednisolone treatment compared with before prednisolone treatment (1.2∓0.3cm/year vs.3.7∓1.2 cm/year,P12 months than those with a 6~12 months course (P0.05). The growth speed of seven children who received rhGH therapy for half a year were increased from 2.2∓0.1cm/year to 7.8∓0.5cm/year (P<0.05), and then to 6.9∓0.4cm/year one year later., Conclusions: The long-term glucocorticoid treatment can decrease the hGH secretion, and thus leads to short stature and agenesis. However, the rhGH replacement can safely and effectively improve growth and development in these children after their primary diseases are improved and glucocorticoids are withdrawn.

Objective: To examine the frequency and distribution of antibodies against pandemic influenza A (H1N1 2009) [H1N1] in populations in Beijing and elucidate influencing factors., Methods: In January 2010, a randomized serologic survey of pandemic influenza A (H1N1 2009) was carried out. Six districts that were randomly selected with a total of 4601 participants involved in the survey have their antibody level tested by hemagglutination inhibition assay., Results: Among the 4601 participants, the overall seropositive rate for pandemic influenza A (H1N1 2009) antibodies was 31.7%. The seropositivity prevalence in participants who received the pandemic H1N1 vaccination was 60.9%. Only 53.1% of the pandemic influenza A (H1N1 2009) seropositive individuals who had not received the vaccination experienced respiratory tract infection symptoms. Multivariate logistic regression revealed that factors such as age, occupation, dwelling type, whether the participant's family included students in school, and the vaccination history with pandemic influenza A (H1N1 2009) were associated with antibody titers (p<0.05)., Conclusions: Our data indicated that almost 30.0% of the residents had appropriate antibody titers against pandemic influenza A (H1N1 2009) in Beijing, and these titers may provide an immune barrier., (Copyright © 2010 Elsevier Inc. All rights reserved.)

The conversion of frequency modulation to amplitude modulation (FM-to-AM) effect is harmful to the high power laser facility based on the phase modulation technique. The FM-to-AM effect of phase modulation pulse induced by the weak etalon effect in wave plates was investigated theoretically and experimentally. A bulk phase modulator with a modulation frequency of 9.2GHz was employed. The numerical simulation results show that the FM-to-AM effect with a temporal modulation depth of 2.5% and 29.7% on the top of the pulse shape was induced by the weak etalon effect in half-wave plate with thickness of 1mm and residual reflectance ratio of 0.5% for 1 pass and 12 passes respectively. On the same condition, the temporal modulation depth is 3.0% and 23.4% respectively in the experiment. The results are in good agreement with numerical simulation results. To our knowledge, it is the first time to introduce the weak etalon effect in wave plates for a complex phase modulation laser system.

Objective: To observe the effects of uremia serum on monolayer permeability and F-actin in cultured rat pulmonary microvascular endothelial cell (RPMVEC) and to investigate the mechanism of injury of RPMVEC induced by uremia serum., Methods: RPMVEC was isolated and cultured from Wistar rat in vitro. The effects of serum of uremia patients on monolayer permeability of RPMVEC were observed with microfilter, and F-actin expression was evaluated by flow cytometry., Results: Serum of uremia patients induced the increased permeability of RPMVEC monolayer for 6 h and 12 h (P < 0.01), depolymerization of F-actin for 6 h and 12 h (P < 0.01), the increased permeability of RPMVEC monolayer induced by serum of uremia patients is significantly correlated with the depolymerization of F-actin (r = -0.927, P < 0.01)., Conclusion: Serum of uremia patients may induce the elevation of permeability monolayer and the depolymerization of F-actin in RPMVEC. The elevation of permeability monolayer induced by serum of uremia patients in RPMVEC is significantly correlated with the depolymerization of F-actin.

A new coupling method is proposed for high-power laser-diode-array (LDA) end-pumped large-aperture amplifiers. In this method, stacks in the LDA are distributed on a spherical surface, and a hollow duct is placed after them. Both numerical simulations and experimental research have been done for this method. All results show that high coupling efficiency and uniform pumping field can be obtained simultaneously using this method.

This report documents an analysis of post-traumatic neurodegeneration during the first 7 days after controlled cortical impact (CCI) traumatic brain injury (TBI) in mice and rats using the de Olmos aminocupric silver staining method, which selectively stains degenerating axons and nerve terminals, compared to the fluorojade method, which stains degenerating neuronal cell bodies. A progressive increase in cortical, hippocampal, and thalamic degeneration was observed over the first 48 h after injury in both species. Approximately 50% of the ipsilateral cortical volume was stained at 48 h. Similarly, the dorsal hippocampus showed widespread degeneration in all of the subfields. This included CA1, CA3, CA4, and dentate cell bodies revealed by fluorojade together with a high degree of axonal degeneration in areas carrying afferent and efferent hippocampal projections that is identified by silver staining. These results show that previous CCI studies which have relied on conventional histological methods that show cell body staining alone have underestimated the degree of axonal damage associated with the CCI-TBI model. In order to capture the full extent of the injury to both axons and cell bodies, the combination of silver staining and fluorojade staining is needed, respectively. Future studies of potential neuroprotective agents should probably not rely on the measure of cortical lesion volume or volume of spared cortical tissue using conventional histological stains alone, since these fail to identify the complete extent of the posttraumatic neuropathology that some agents which reduce cortical lesion volume may not be able to effect.

Objective: To investigate whether the expression and function of aquaporin-1 (AQP-1) is altered by tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) in primary rat lung microvessel endothelial cells (LMECs) after exposure to lipopolysaccharide (LPS), and to study the expressions of AQP-1 and AQP-5 in lung tissue of rats with acute lung injury (ALI) induced by LPS. The aim is to further clarify the pathogenesis of ALI/acute respiratory distress syndrome (ARDS)., Methods: (1) In vitro: The third passage LMECs were randomly divided into LPS group, TNF-alpha group, IL-1beta group and DMEM control group, and the experimental groups were exposed to LPS, TNF-alpha and IL-1beta respectively. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to quantify AQP-1 mRNA changes and an immunocytochemistry method was used for determining AQP-1 protein changes in cultured rat LMECs. Isotope tracer technique was applied for the assay of the intra-cellular tritium water ((3)H2O) signal intensity in rat LMECs. (2) In vivo: Forty male Wistar rats were randomly divided into five groups: LPS 2 h group, LPS 4 h group, LPS 6 h group, LPS 8 h group and a control group, eight rats per group; The LPS treated groups served as the ALI models. RT-PCR was used to observe the changes of AQP-1 and AQP-5 mRNA and the immunohistochemistry method was used for determining AQP-1 and AQP-5 protein changes in ALI rats., Results: (1) In vitro: The expression of AQP-1 mRNA and protein in LMECs were decreased significantly in the LPS group (0.428 +/- 0.026, 0.366 +/- 0.009), the TNF-alpha group (0.446 +/- 0.029, 0.374 +/- 0.014) and IL-1beta group (0.454 +/- 0.023, 0.377 +/- 0.007) as compared to the DMEM control group (0.793 +/- 0.035, 0.660 +/- 0.013, respectively; all P < 0.01). The quantities of tritium water's permeability in the LPS group, the TNF-alpha group and the IL-1beta group [(726 +/- 58), (738 +/- 45), (774 +/- 44) counts per minute] were significantly less than that in the DMEM control group [(1 148 +/- 70) counts per minute, P < 0.01]. (2) In vivo: The expression levels of AQP-1 and AQP-5 mRNA in ALI rats (LPS 2 h group 0.409 +/- 0.018, 0.421 +/- 0.020; LPS 4 h group 0.421 +/- 0.023, 0.412 +/- 0.023; LPS 6 h group 0.435 +/- 0.020, 0.388 +/- 0.031; LPS 8 h group 0.438 +/- 0.016, 0.386 +/- 0.019, respectively) were significantly lower than that in the control group (0.794 +/- 0.015, 0.787 +/- 0.022; all P < 0.01)., Conclusion: AQP-1 and AQP-5 may play a role in abnormal fluid transportation and probably involve in the formation of pulmonary edema in ALI/ARDS.

Objectives: Cariostatic effects of lasers have been well documented in the past few decades; however, the mechanisms remain unclear. Our previous study revealed the statistically significant effect of organic matrix (OM) in the laser-induced caries prevention. The aim of the present study is to further investigate the role of organic matters in the laser-induced porosity changes., Methods: Enamel powder from five sound molars was randomly divided into two samples. One sample was treated with approximately 10% NaClO solution to remove OM and the other was left untreated. Both groups were then subjected to irradiation by an Er:YAG laser. The samples were characterized by thermogravimetric analysis (TGA) and N(2) physico-adsorption., Results: TGA results confirmed that the NaClO treatment had at least partially removed the OM in enamel powder. The surface area and pore volume of normal enamel powder decreased significantly after laser treatment. In contrast, in the NaClO-treated enamel powder, laser treatment did not significantly decrease the surface area and the pore volume remained almost unchanged. The substantial difference between the normal enamel powder and the NaClO-treated enamel powder after laser treatment confirmed the laser-induced blocking of OM in the micro-diffusion pathway in enamel., Conclusion: The findings in this study seemed to substantiate the "organic blocking theory" as one of the mechanisms in the laser-induced caries prevention.