Pengaruh Pengawetan terhadap Kekuatan dan Keawetan Produk Laminasi Bambu

The need of housing corresponds with the increasing population growth. Such condition affects the demand of timber used for building construction. On the other hand, the government extremly minimizes forest logging to protect the forest from degradation. To solve the problem of increasing need of timber, one of the efforts is by utilzing bamboo as local materials for laminated products. However besides the advantages, bamboo is a susceptible material for organism. Improving the durability of bamboo againts organism can be achieved through preservation.This research (study) is aimed to recognize the effect of bamboo preservation to the strength and durability of laminated bamboo. In this study, Petung bamboo (Dendrocalamus sp) was treated with boron plus 63% preservative with the concentration of 1.57% and 3.15% using Bouherie-Morisco method with 3 kg/cm2 and 4kg/cm2 air pressure. The glulam bamboos in 25 mm x 30 mm x 2000 mm dimension were made from preserved bamboo with polimer isocyanate adhesive in 50#/MSGL under 1.2 Mpa pressure. Untreated bamboo were used as control for each treatment, 3 aplications were applied. Results of this research showed that moisture content was affected by the preservation pressure. The preservation treatments were not affected by the density, compressive strength parallel to the grain, tensile strength parallel to the grain, internal bond strength, horizontal bending strength, vertical bending strength, horizontal modulus of elasticity, vertical modulus of elasticity of the tested glulam bamboo as well as retention of preservatives was affected by the concentration of preservatives or the pressure of the treatment. The treatment method affected the termites mortality percentage but not the mass lost percentage. The physical and mechanical properties of treated bamboo was not indefference to the untreated bamboo. There was a tendency that mass lost precentage in untreated bamboo was higher than in treated bamboo while the termite mortality percentage in treated bamboo was lower than un treated bamboo

Pengaruh Ekstrak Tembakau Terhadap Sifat Dan Perilaku Mekanik Laminasi Bambu Petung

Timber supply is diminishing in addition to the trend to lower quality but higher cost of wood production manufacturing. However, because the demand of this material continues, an alternative or substitution on the use of timber, such as bamboo laminated, is desirable. Having susceptible character to powder by beetles attack, bamboo must be passed through preservation process before it is applied as laminating materials, but chemical preservative materials used in industrial process bring negative impacts to the environment. One of human and environmental friendly preservatives is the tobacco extract. Nevertheless, the most effective concentration of tobacco extract and its influence to the adhesive materials have not been well recognized. This research objective was to investigate the influence of tobacco extract to the natural and mechanic behaviour of laminated bamboo. Dried tobacco flake was mixed with water in variable concentration of 100, 125, 150 and 175 gram/liter. Bamboo split were given treatment in boiling water with tobacco extract solutions. As benchmarking, bamboo split also preserved with boiling water (without preservatives materials) and 5% concentration of borax. Non preservative bamboo was used as the control. The result of experiment showed that tobacco extract concentration of 150 gram/liter caused 61,33% insect mortality and 1,87% decreased weigh, which is effective to be used as preservative in compare to other three concentrations. Water content and density observation showed that preservation using 150 gram/liter extract tobacco comparing to non preservative boiling preservation, produced smaller value of water content and larger value of density than borax preservative. Preservation using 150 gram/liter tobacco extract produced highest value of compression parallel to grain and modulus of the bamboo elasticity Petung mechanic properties were 277,95 MPa and 170,34 MPa, respectively. Mechanical properties of laminated bamboo that were significantly influenced by preservative variation showed that highest values for compression parallel to grain and modulus of elasticity were 66,09 MPa and 127,12 MPa, respectively and reached by preservation using 100 gram/liter tobacco extract

Kuat Tekan Bambu Laminasi dan Aplikasinya pada Rumah Tradisional Bali (Bale Daje/bandung)

Building material technological development recently is very fast, and in every technological innovation creation, it's inspired by some of the main purpose, such as: cost efficiency, material use optimization, conservation and development of natural material, smart building material technology and ecologically friendly. Lamination bamboo technology is a product that can act as substitution material of wood that can be customized with the need. In the effort to support the innovation of lamination bamboo as a wood substitution in Balinese traditional building, the characteristic mechanics of lamination bamboo as column in supporting axial loading should be known. Lamination bamboo for the experiemnt was made in the form of column with two kind of longitudinal section dimension, size 20x20 mm with slenderness value (λ) of 50, 75, 100, 125, and 150, and size 120x120 mm with the length of 2400 mm (as the dimension in Balinese traditional building). The bamboo used were petung bamboo made of blade about 5x20 mm attached to glue of Urea Formaldehyde (UF) and pressed with a pressure of 2,0 MPa. The research stage was physical property test and the mechanic of petung bamboo material, and continued with a process of making the lamination bamboo column and carving. Pressure axial loading for testing of column the lamination bamboo used hinge placement bamboo until maximum loading, big deformation and not until collapse. The technological innovation of lamination bamboo was able to increased the pressure strength of blade until 36,02% compared to the bamboo material used. The role of glue and pressing given a substantial contribution on pressure strength of lamination bamboo, so besides having a capability to be made with dimension and form us want, lamination bamboo also had high pressure strength. Lamination bamboo pressure strength of petung bamboo in variety of slenderness had pressure strength less with the higher slenderness. The pressure voltage in the smallest slenderness, λ=50 is 60,093 MPa until the blade with the highest slenderness, λ=150 is 12,946 MPa while for the plain and carved structural model they were 25,578 MPa and 23,529 Mpa respectively. The formula of proposal in column pressure strength modeling of lamination bamboo material for for λ λb, σtk = (π2E)/λ r2. The treatment of carving in structural lamination bamboo column weakens the support to average axial load of 41,15% and the decrease of average pressure voltage of 8,009%

Pengaruh Compaction Ratio Terhadap Sifat Papan Lantai Partikel Kayu Jati Dan Sengon

Wood particle board is one of building materials which can be used as floor like solid wood. To utilize particle boards with appropriate compaction ratio, study should be conducted to know the influence of compaction ratio on the particle board characteristics of two wood species namely teak and sengon, and the research result could be used as a base of the assessment to particle board for building. The preliminary test was done to know the density of teak and sengon wood. This study used teak and sengon wood particles with 10% by weight of particle urea formaldehyde adhesive UA-147. This study was arranged in the completely randomised design with factorial experiment. The factors in this experiment were compaction ratio and wood species, while the parameters which observed were density, water content, water absorption, thickness swelling, internal bonding, hardness, MOE, and MOR. The research result showed that the higher compaction ratio, the higher density, internal bonding, hardness, MOR and MOE of both species particle board, the higher thickness swelling, and the lower water absorption of sengon particle board. The highest average density of the teak particle board was 0,80 g/cm3 (J1K3) and 0,67 g/cm3 for sengon (J2K6). The highest average internal bonding of the teak particle board was 5,20 kg/cm2 (J1K3) and 5,85 kg/cm2 for sengon (J2K6). The highest average hardness of the teak particle board was 666,7 kg/cm2 (J1K3) and 533,3 kg/cm2 for sengon (J2K6). The highest average MOR of the teak particle board was 145,9 kg/cm2 (J1K3) and 162,7 kg/cm2 for sengon (J2K6). The highest average thickness swelling of the sengon particle board was 30,76% (J2K4) and 11,84% the lowest (J2K3). The highest average MOE of the sengon particle board was 18605,45 kg/cm2 (J2K6) and 22580,41 kg/cm2 for the teak (J1K3). The highest average water absorption of the sengon particle board was 170,30% (J2K1) and 72,12% the lowest (J2K6). With the same compaction ratio of the teak and sengon particle board, the teak wood species had the better physic and mechanic characteristics than sengon. Based on the comparation result with some industries standard of the particle board, it showed that particle boards J2K1, J2K2, and J2K3 did not correspond to some industries standard

Naposomes: a new class of peptide-derivatized, target-selectivemultimodal nanoparticles for imaging and therapeutic applications

Modified supramolecular aggregates for selective delivery of contrast agents and/or drugs are examined with a focus on a new class of peptide-derivatized nanoparticles: naposomes. These nanoparticles are based on the co‑aggregation of two different amphiphilic monomers that give aggregates of different shapes and sizes (micelles, vesicles and liposomes) with diameters ranging between 10 and 300 nm. Structural properties and in vitro and in vivo behaviors are discussed. For the high relaxitivity values (12–19 mM-1s-1) and to detect for the presence of a surface exposed peptide, the new peptide-derived supramolecular aggregates are very promising candidates as targetselective MRI contrast agents. The efficiency of surface-exposed peptides in homing these nanovectors to a specific target introduces promising new opportunities for the development of diagnostic and therapeutic agents with high specificity toward the biological target and reduced toxic side effects on nontarget organs

Amphiphilic CCK peptides assembled in supramolecular aggregates: structural investigations and in vitro studies

Supramolecular aggregates obtained by self-aggregation of five new cationic amphiphilic CCK8 peptides have been obtained in water solution and characterized for: (i) aggregate structure and stability; (ii) CCK8 peptide conformation and bioavailability on the external aggregate surface; and (iii) for their cell binding properties. The cationic amphiphilic CCK8 peptides self-aggregate giving a combination of liposomal and micelle structures, with radii ranging between B60 nm and B90 nm, and between B5 and B10 nm, respectively. The presence of CCK8 peptide well-exposed on the aggregate surface is demonstrated by fluorescence measurements. Peptide conformation changes in the five supramolecular aggregates: the CCK8 conformational behaviour is probably induced by the presence of three charged lysine residues close to the bioactive peptide sequence. Only aggregates in which the CCK8 peptide presents a structural arrangement similar to that found for the same peptide in DPC micelles give promising binding properties to CCK2-R receptors overexpressed by transfected A431 cells. Chemical modifications on the CCK8 N-terminus seem to play an important role in stabilizing the peptide active conformation, either when the peptide derivative is in monomeric or in aggregate form. For their easy preparation procedures and their binding properties, supramolecular aggregates based on cationic peptide amphiphiles can be considered as promising candidates for target selective drug carriers on cancer cells

Pre-clinical evaluation of eight DOTA coupled gastrin-releasing peptide receptor (GRP-R) ligands for in vivo targeting of receptor-expressing tumors

Background: Overexpression of the gastrin-releasing peptide receptor (GRP-R) has been documented in several human neoplasms such as breast, prostate, and ovarian cancer. There is growing interest in developing radiolabeled peptide-based ligands toward these receptors for the purpose of in vivo imaging and radionuclide therapy of GRP-R-overexpressing tumors. A number of different peptide sequences, isotopes, and labeling methods have been proposed for this purpose. The aim of this work is to perform a direct side-by-side comparison of different GRP-R binding peptides utilizing a single labeling strategy to identify the most suitable peptide sequence. Methods: Solid-phase synthesis of eight derivatives (BN1-8) designed based on literature analysis was carried out. Peptides were coupled to the DOTA chelator through a PEG4 spacer at the N-terminus. Derivatives were characterized for serum stability, binding affinity on PC-3 human prostate cancer cells, biodistribution in tumor-bearing mice, and gamma camera imaging at 1, 6, and 24 h after injection. Results: Serum stability was quite variable among the different compounds with half-lives ranging from 16 to 400 min at 37 °C. All compounds tested showed Kd values in the nanomolar range with the exception of BN3 that showed no binding. Biodistribution and imaging studies carried out for compounds BN1, BN4, BN7, and BN8 showed targeting of the GRP-R-positive tumors and the pancreas. The BN8 compound (DOTA-PEG-DPhe-Gln-Trp-Ala-Val-NMeGly-His-Sta-Leu-NH2) showed high affinity, the longest serum stability, and the highest target-to-background ratios in biodistribution and imaging experiments among the compounds tested. Conclusions: Our results indicate that the NMeGly for Gly substitution and the Sta-Leu substitution at the C-terminus confer high serum stability while maintaining high receptor affinity, resulting in biodistribution properties that outperform those of the other peptides

The bisphenol a induced oxidative stress in non-alcoholic fatty liver disease male patients: A clinical strategy to antagonize the progression of the disease

Introduction: Bisphenol A (BPA) exposure has been correlated to non-alcoholic fatty liver disease (NAFLD) development and progression. We investigated, in a clinical model, the effects of the administration of 303 mg of silybin phospholipids complex, 10 μg of vitamin D, and 15 mg of vitamin E (RealSIL, 100D, IBI-Lorenzini, Aprilia, Italy) in male NAFLD patients exposed to BPA on metabolic, hormonal, and oxidative stress-related parameters. Methods: We enrolled 32 male patients with histologic diagnosis of NAFLD and treated them with Realsil 100D twice a day for six months. We performed at baseline clinical, biochemical, and food consumption assessments as well as the evaluation of physical exercise, thiobarbituric acid reactive substances (TBARS), plasmatic and urinary BPA and estrogen levels. The results obtained were compared with those of healthy control subjects and, in the NAFLD group, between baseline and the end of treatment. Results: A direct proportionality between TBARS levels and BPA exposure was shown (p < 0.0001). The therapy determined a reduction of TBARS levels (p = 0.011), an improvement of alanine aminotransferase, aspartate aminotransferase, insulinemia, homeostatic model assessment insulin resistance, C reactive protein, tumor necrosis factor alpha (p < 0.05), an increase of conjugated BPA urine amount, and a reduction of its free form (p < 0.0001; p = 0.0002). Moreover, the therapy caused an increase of plasmatic levels of the native form of estrogens (p = 0.03). Conclusions: We highlighted the potential role of BPA in estrogen oxidation and oxidative stress in NAFLD patients. The use of Realsil 100D could contribute to fast BPA detoxification and to improve cellular antioxidant power, defending the integrity of biological estrogen-dependent pathways

Bombesin peptide antagonist for target-selective delivery of liposomal doxorubicin on cancer cells

Purpose: This study addresses novel peptide modified liposomal doxorubicin to specifically target tissues overexpressing bombesin (BN) receptors. Methods: DOTA-(AEEA)2-peptides containing the [7–14]bombesin and the new BN-AA1 sequence have been synthesized to compare their binding properties and in serum stabilities. The amphiphilic peptide derivative (MonYBN- AA1) containing BN-AA1, a hydrophobic moiety, polyethylenglycole (PEG), and diethylenetriaminepentaacetate (DTPA), has been synthesized. Liposomes have been obtained by mixing of MonY-BN-AA1 with 1,2-distearoylsn-glycero-3-phosphocholine (DSPC). Results: Both 111In labeled peptide derivatives present nanomolar Kd to PC-3 cells. 177Lu labeled peptide DOTA- (AEEA)2-BN-AA1 is very stable (half-life 414.1 h), while DOTA-(AEEA)2-BN, shows a half-life of 15.5 h. In vivo studies on the therapeutic efficacy of DSPC/MonY-BN-AA1/Dox in comparison to DSPC/MonY-BN/Dox, were performed in PC-3 xenograft bearing mice. Both formulations showed similar tumor growth inhibition (TGI) compared to control animals treated with non-targeted DSPC/Dox liposomes or saline solution. For DSPC/MonY-BN-AA1/Dox the maximum effect was observed 19 days after treatment. Conclusions: DSPC/MonY-BN-AA1/Dox nanovectors confirm the ability to selectively target and provide therapeutic efficacy in mice. The lack of receptor activation and possible acute biological side effects provided by using the AA1 antagonist bombesin sequence should provide safe working conditions for further development of this class of drug delivery vehicles

Risk factors for liver decompensation and hcc in hcv-cirrhotic patients after daas: A multicenter prospective study

Background: Prospective studies on predictors of liver-related events in cirrhotic subjects achieving SVR after DAAs are lacking. Methods: We prospectively enrolled HCV cirrhotic patients in four Italian centers between November 2015 and October 2017. SVR and no-SVR cases were compared according to the presence or absence of liver-related events during a 24-month follow-up. Independent predictors of liver-related events were evaluated by Cox regression analysis. Results: A total of 706 subjects started DAAs therapy. SVR was confirmed in 687 (97.3%). A total of 61 subjects (8.9%) in the SVR group and 5 (26.3%) in the no-SVR group had liver-related events (p < 0.03). The incidence rate x 100 p/y was 1.6 for HCC, 1.7 for any liver decompensation, and 0.5 for hepatic death. Baseline liver stiffness (LSM) ≥ 20 kPa (HR 4.0; 95% CI 1.1–14.1) and genotype different from 1 (HR 7.5; 95% CI 2.1–27.3) were both independent predictors of liver decompensation. Baseline LSM > 20 KPa (HR 7.2; 95% CI 1.9–26.7) was the sole independent predictor of HCC. A decrease in liver stiffness (Delta LSM) by at least 20% at the end of follow-up was not associated with a decreased risk of liver-related events. Conclusion: Baseline LSM ≥ 20 kPa identifies HCV cirrhotic subjects at higher risk of liver-related events after SVR