Impact of the mouse model and molar amount of injected ligand on the tissue distribution profile of PSMA radioligands

Purpose Various preclinical study designs are described in the literature for the evaluation of PSMA radioligands. In this study, [177Lu]Lu-Ibu-DAB-PSMA, an albumin-binding radioligand, and [177Lu]Lu-PSMA-617 were investigated and compared under variable experimental conditions. Methods In vitro cell uptake studies were performed with PC-3 PIP and LNCaP tumor cells using a range of molar concentrations (0.75–500 nM) of both radioligands. Biodistribution and SPECT/CT imaging studies were carried out with the respective tumor mouse models using 0.05 nmol and 1.0 nmol injected ligand per mouse. Results In both tumor cell lines, the uptake of the radioligands was increased when using low molar concentrations of the respective ligand. The observed saturation effect at high ligand concentrations was more pronounced for LNCaP cells that express PSMA at lower levels than for PC-3 PIP cells. At all investigated timepoints, the in vivo uptake of both radioligands was higher in PC-3 PIP tumors than in LNCaP tumors. A low molar amount of injected ligand increased the PC-3 PIP tumor uptake mainly for [177Lu]Lu-Ibu-DAB-PSMA; however, the molar amount of ligand was relevant for both radioligands when using LNCaP tumors. Renal retention of both radioligands was, however, up to fourfold higher during the first hours after application of a low ligand amount compared to the high ligand amount. Conclusion The results of this preclinical study underline the relevance of the tumor model and applied ligand amount for the characterization of PSMA radioligands. The application of equal preclinical study designs is crucial to allow the comparison of novel radioligands with existing ones and, thus, predict potential advantages of new radioligands in view of a clinical application.

Staphylococcus Derived from Desert and Its Solidified Ability on Aeolian Sandy Soil

Many soil microorganisms in nature induce carbonate precipitation, which is used in soil improvement to reduce the pollution of soil environment by traditional chemical improvement. With the goal of expanding the geotechnical applications of biomineralizing bacteria, this study investigated the characteristics of a newly identified strain of soil bacteria, including its mineralization ability, its effect on Aeolian sandy soil, and biomineralization crust effect in the desert field test. The autogenous mineralized strain was isolated and purified from desert Aeolian sandy soil, and the strain was identified as Staphylococcus using 16SrRNA sequence homology. It is a kind of mineralized bacteria seldom used in geotechnical engineering at present, and it was found to have good mineralization ability; the living conditions of Staphylococcus were optimized. Under the determined amount of bacteria liquid, the amount of calcium carbonate precipitation after the bacteria liquid reacted with different volumes of calcium source solution was studied to determine the appropriate ratio of bacteria liquid and calcium source solution and the molar amount of calcium source solution. This study also investigated the effect of mineralization on the strength of sand and determined the particle size range of sand and suitable bacteria concentration that Staphylococcus can effectively stabilize. Field test results verified desert autogenous Staphylococcus had a good mineralization effect on sand. It was suitable for Aeolian sandy soil crust and improvement. In this paper, the autogenous strain was applied to the surface of the desert for the first time to form an in situ microbial mineralization crust. The research results can provide a theoretical basis for the better application of autogenous strain in the desert.

MOLAR AMOUNT OF WATER

When modeling body fluids using physical chemistry, we en-countered a contradiction. We proceeded from the erroneous assumption that the molar amount of water in an aqueous so-lution is the molar amount of H2O molecules (mass divided by the mass of one H2O molecule). Thus, in one kilogram of pure water, we calculated 55.508 moles of water because the molar mass of H2O is 18.01528 g / mol. When calculating the molar fractions as the molar amount of the substance divided by the solution's total molar amount, we thus obtained numerically completely different values than for molalities or molarities. According to the theory, these values should be substitutable. However, it turned out that using these values in the calculati-ons of the solubility of gases in aqueous solutions showed us an error of about 55 mol/kg. Similar errors began to be reported for chemical processes with different numbers of reactants and products (at the same number, the error is annulled algebrai-cally). So is the water molality really about 55 mol/kg? No. This is because water forms bonds with each other, which cluster more H2O molecules into larger particles. From the required molar amount of water, we derived the dissociation constant and enthalpy of this bond. The results are compatible with data from the National Institute of Standards and Technology (NIST) and the data of formation energies of individual substances. Using these constants, it is possible to derive the molar amount of water in aqueous solutions and subsequently make calculati-ons over molar fractions, the results of which begin to coincide with the measured and published experiments.

Low-temperature reduction of acyclic carvomentholactone derivatives with diisobutylaluminum hydride in methylene chloride

Earlier, we discovered a novel reaction in the chemistry of organoaluminum compounds - the formation of O-isobutyl acetals during low-temperature (-70 °С) treatment of a number of seven-membered lactones with a twofold (or more) molar amount of diisobutylaluminium hydride in methylene chloride. In addition, it was shown that the acyclic derivatives of (-)-mentholactone - methyl 6-hydroxy-3,7-dimethyl-octanoate and its 6-oxo analogue - also enter into the low-temperature reduction reaction of diisobutylaluminum hydride in methylene chloride. Moreover, methyl 6-hydroxy-3,7-dimethyloctanoate in this reaction behaves similarly to (-)-mentholactone: when 4 equivalents of diisobutylaluminium hydride acts on it, the reaction proceeds with the predominant formation of isobutyl acetal as the only (2S,7S)-epimer. Methyl 6-oxo-3,7-dimethyl octanoate in a low-temperature reduction reaction with 4 equivalents of diisobutylaluminium hydride in methylene chloride acts as a mixture of (-)-mentholactone and isomentolactone, leading to a mixture of (2S,7S)-, (2S,7R)- and (2R,7R)-isobutyl acetals in a ratio of 3.2: 1.3: 1.0, respectively. In the present work, when low-temperature reduction was involved in the reaction with diisobutylaluminium hydride, methyl (3R)-6-hydroxy- or (3R)-6-oxo-3-isopropylheptanoates available from carvomentolactone reacted without the formation of isobutyl acetal: a mixture of (2: 1) 6-hydroxy-(3R)-isopropylheptanal and (4R)-isopropyl-7-methyloxepan-2-ol was obtained.

Sintesis biodisel dengan teknik ozonasi : ozonolisis etil-ester minyak sawit sebagai suatu bahan bakar mesin diesel alternatif

Conventional biodiesel synthesis through transesterification reaction pathway of the palm oil or other vegetable oils has been regarded yet as a steep process, mainly to be implemented as fuel for various diesel engines in Indonesia. The methanol consumption for such process is still costly as well, especially 2-3 times of free fatty acid (FFA) molar amount, which is dangerous as methanol being classified as hazardous chemicals, while the yield of palm oil methyl ester (POME) is just 70%­ volume roughly. The ozonide biodiesel synthesis is considered as a better alternative, which is quasi­-parallel ozonolysis reaction application in the conventional transesterification schema using ethanol to produce ozonide biodiesel or ozonide methyl-ester. The ozone gas being applied to the process is produced in situ by an ozone generator apparatus, using fresh and purified air as oxygen source, with about 5,5 g/h ozone production at 400-800 L/h air or feed flowrate. The ozonide biodiesel is favorable to ethanol (96 %-v) being used as reactant and or protic solvent than methanol, even using catalyst (zeolite/GAC) or not, at 55-72ºC and atmospheric condition. The ethanol utilization may be saved until 31,15-39,85 %-mol of conventional biodiesel process. The results obtained from the investigations give some interesting characteristics comparing to diesel fuel in Indonesia, especially better values of cetane index, BHP and torque.Keywords: Palm Oil, Biodiesel, Methyl Ester, Ethyl Ester, Ozonide, Ozonolysis AbstrakReaksi transesterifikasi yang diterapkan untuk sintesis biodiesel dari minyak sawit ataupun minyak­ minyak nabati lainnya dianggap belum memberikan perolehan yang ekonomis untuk pengadaan bahan bakar untuk mesin-mesin diesel di Indonesia. Penggunaan metanol sebesar 2-3 kali jumlah molar asam-asam lemak bebasnya (ALB) adalah tidak ekonomis sekaligus berbahaya mengingat sifatnya sebagai bahan kimia beracun dan berbahaya (B3), sedangkan perolehan metil ester dari minyak saw it atau Palm Oil Methyl Ester (POME) hanya sekitar 70 %-v. Sintesis biodiesel ozonida dianggap sebagai alternatif yang lebih baik, yaitu aplikasi reaksi ozonolisis secara kuasi paralel dalam reaksi transesterifikasi tersebut menggunakan etanol, sehingga dihasilkan biodiesel atau etil­ester ozonida. Ozon yang digunakan merupakan produk in situ dari ozonator dengan bahan baku udara, pada laju produksi ozon sekitar 5,5 gram/jam dengan alir udara umpan 400-800 L/jam. Sintesis biodiesel ozonida ini lebih menyukai etanol (96%-v) sebagai pelarut protik dibandingkan dengan metanol, baik menggunakan katalis (zeolit/GAC) maupun tanpa katalis, pada suhu 55-72ºC dan tekanan atmosferik. Penggunaan etanol dapat dihemat sampai sekitar 31,15-39,85 %-mol dari jumlah yang diperlukan untuk sintesis biodiesel konvensional. Dari hasil uji kinerja produk biodiesel ozonidanya, didapatkan informasi tentang indeks setana, daya, dan torsi yang lebih baik dari minyak solar di Indonesia.Kata Kunci: Minyak Sawit, Biodiesel, Metil Ester, Etil Ester, Ozonida, Ozonolisis

Sintesis minyak goreng sehat (Diacylglycerol)

The syntesis of healty cooking oil (Diacylglycerol)Diglyceride I Diacylglycerol (DAG) oil is a compound resulting from the chemical bonding between glycerol and two free fatty acid molecules which follows a different metabolic route compared to triglyceride-type oils so that this type of oil does not cause fat accumulation in the body. This research isfocused at obtaining experimental evidence from the Archer-Daniels-Midland (2002) synthesis method, identifying the effect of the molar ratio between the reactants and reaction time on the DAG yield using the glycerolysis method, and at synthesizing a cooking oil with diglycerides as its major component. The diglyceride synthesis process in this research was done via glycerolysis with a varying glycerol : TAG ratio of 1:1, 3:2, 2:1 and 5:2. Reaction time was varied at 1 and 3 hours. The synthesis was undertaken at 190°C, using CH3COOK as catalyst at a dose of 1% of the mass ofTAG reactant. Experimental results indicate that longer reaction time increases the molar amount of diglycerides formed in the healthy cooking oil product. The molar ratio of glycerol to triglycerides which produces the highest DAG yield was 2:1, with a reaction time of 3 hours, which resulted in a yield of 97. 726%-mol DAG per mol TAG reactant. Higher molar ratio of glycerol to tryglycerides also increases the percentage of monoglycerides (MAG)formed.Keywords: DAG (Diglycerides), glycerolysis, TAG (Triglycerides) AbstrakMinyak Digliserida/Diacylglycerol (DAG) adalah senyawa hasil ikatan kimia antara g/iserol dengan 2 buah asam lemak bebas yang mengikuti jalur metabolik yang khas dan berbeda dengan jenis minyak trigliserida sehingga tidak menyebabkan penimbunan lemak dalam tubuh. Penelitian ini bertujuan untuk mendapat bukti eksperimental dari metode Archer-Daniels-Midland (2002), mengetahui pengaruh rasio mol reaktan dan waktu reaksi terhadap perolehan DAG dari metode gliserolisis dan mendapatkan hasil minyak goreng yang memiliki kandungan utama digliserida. Proses sintesa digliserida dalam penelitian ini dilakukan dengan reaksi gliserolisis yang menggunakan variasi rasio reaktan gliserol : TAG 1:1, 3:2, 2:1 dan 5:2. dengan dan variasi waktu 1 dan 3 jam. Sintesa ini berlangsung pada temperatur 190°C dan menggunakan katalis CH3COOK sebanyak 1% dari berat TAG yang digunakan. Hasil penelitian menunjukkan bahwa semakin lama waktu reaksi gliserolisis, semakin tinggi jumlah mol dig/iserida yang terbentuk di dalam minyak goreng sehat. Rasia mol reaktan gliserol: trigliserida yang menghasilkan perolehan DAG tertinggi adalah rasio 2:1 dengan waktu reaksi 3 jam, yaitu sebesar 97, 726%-mol DAG per mol TAG mula-mula. Semakin tinggi rasio mol reaktan gliserol : trigliserida, %-monogliserida (MAG) yang terbentuk juga semakin tinggi.Kata Kunci: DAG (Digliserida), gliserolisis, TAG (Trigliserida)

HYBRID SILANE TECHNOLOGY IN SILICA-REINFORCED TREAD COMPOUND

ABSTRACT The use of a silane coupling agent in silica-reinforced tread can effectively improve silica dispersion in the rubber matrix and strengthen the interfacial interaction between the rubber and filler; this is beneficial to the enhancement of tire grip under wet conditions and reduces tire rolling resistance. The monofunctional silane n-octyltriethoxysilane (OTES) can react with the silanol group of the silica surface and hence improve silica dispersion. It can also suppress silica reaggregation during tire processing. Two hybrid silanes, OTES and 3-mercaptopropylethoxy-bis(tridecyl-pentaethoxy-siloxane) (Si747) or OTES and bis(triethoxysilylpropyl)tetrasulfide (TESPT), were filled in silica-reinforced tread compounds. The effect of the two hybrid silanes on the silica was investigated via Fourier transform infrared spectroscopy and thermogravimetric analysis. The processing ability of the silica-filled compounds and the performance of the vulcanizates were also investigated. Our experimental results show that OTES is able to further react with the silica following reaction between the TESPT and silica and that it should be added when the molar amount of TESPT or Si747 is constant, to prevent reduction of the cross-link density. Furthermore, the addition of OTES can extend the scorch time, especially in Si747 and OTES compounds. In addition, OTES can improve silica dispersion and only has a slightly negative effect on the physical properties of vulcanizates.

Effect of CaO on Phase Composition and Properties of Aluminates for Barium Tungsten Cathode

6BaO·xCaO·2Al2O3 (x = 0.8, 1.2, 1.6, 2, and 2.2) aluminates were synthesized via a liquid phase co-precipitation method. Effects of the molar amount of CaO on the phase of aluminates before and after melting and their hygroscopic phase, melting properties, environmental stability, evaporation, and emission properties were systematically studied. The results show that with the increase of the molar amount of CaO, the aluminates change from a mixture phase to a single phase of Ba3CaAl2O7, and the diffraction peak shifts to a higher angle. The melted phase of the aluminates changed from a single phase to a mixed phase of Ba5CaAl4O12 and Ba3CaAl2O7. Meanwhile, the comprehensive properties of the aluminates are improved. The weight gain of 6BaO·2CaO·2Al2O3 aluminates is only 10.88% after exposure to air for 48 h; the pulse emission current density of barium tungsten cathodes impregnated with 6BaO·2CaO·2Al2O3 aluminates in the porous tungsten matrix can reach 28.60 A/cm2 at 1050 °C, and the evaporation rate is 2.52 × 10−10 g/(cm2·s).

Study on the Preparation and Characterization of Carboxyl Terminated Poly(L-Lactic Acid) (PLLA) Prepolymers

The carboxyl terminated poly (L-lactic acid) (PLLA) prepolymers were prepared via polycondensation of L-lactic acid and 1,6-adipic acid (end capping agent) under the catalyst of stannous octoate. The effects of synthetic condition, such as reaction temperature, amount of catalyst, content of the end capping agent, etc, on the molecular weight of PLLA were discussed. Fourier transform infrared and 1H nuclear magnetic resonance were used to characterize the PLLA prepolymers. The results indicated that the polycondensation was performed under an optimum reaction condition as following: the amount of the catalyst was 500 ppm based on the mass of lactic acid, the amount of the end capping agent was 1% (the molar amount of the lactic acid), and the polymerization temperature was 170 °C. The viscosity-average molecular weight of the product reached 2.826×104 at this polymerization temperature and the yield was 73.34%.