The Influence of Hydrophilic Decoration on X-ray Excited Luminescence Nanoparticles to Singlet Oxygen Production

(1) Background: Though X-ray excited photodynamic therapy (X-PDT) breakthrough the bottom neck of PDT application in deep tumor by overcoming light penetration depth limitation, the quantum yield of the hydrophilic X-PDT nanoparticles (NPs) still hampered its further application in vivo. Thus, establishing a proper hydrophilic decoration method which can maximally maintain the quantum yield of X-ray excited luminescent NPs is of urgent demand. (2) Methods: We synthesized NaGdF4: [Formula: see text] (NGF) as X-ray excited luminescent NPs and conducted hydrophilic decoration by two hydrophilic ligands, polyethylene glycol-NH2 (PEG) and cysteamine (Cy) via place exchange reaction, and coupled with photosensitizer (MC540) to form a X-PDT nanosystem. We also conducted experiments in vitro and in vivo to evaluate the efficacy of the X-PDT system. (3) Results: Both PEG and Cy decoration NPs presented excellent emission intensity, which could well excite the coupled photosensitizer MC540 to generate significant X-PDT efficacy under low-dose X-ray radiation. Especially for the NGF-Cy-MC540 treatment group, the cell viability reduced to [Formula: see text]% under 0.3[Formula: see text]Gy radiation and [Formula: see text]% under only 0.1[Formula: see text]Gy radiation, which is the lowest radiation dosage in the literature reports so far. In vivo experiment showed about 36% of tumor inhibition rate under 0.3[Formula: see text]Gy X-ray. Besides, no biotoxicity was observed in NGF groups even in high concentrations, demonstrating good biocompatibility. (4) Conclusions: The hydrophilic decoration method by Cy or PEG via place exchange reaction may pave a brand new way and strategy for X-PDT further clinical application.

Kinetic Monte Carlo Simulations of Electrochemical Oxidation and Reduction of Pt(111)

Kinetic Monte Carlo simulations of electrochemical oxidation and reduction are presented that match many features of the experimentally observed electrochemical and morphological response of Pt(111). Included in the simulation are all relevant microscopic transitions, including the formation of Pt-OH and Pt-O from Pt, surface diffusion of all three species, as well as an effective place exchange diffusion at high potential. A detailed description of this approach to modeling such a complex surface is also presented. Overall, it is found that many features of the Pt(111) CV, including hydroxylation, hysteresis, and surface roughening, can be correlated to events associated with n-coordinated surface species, such as the hydroxylation wave corresponding to a one-electron oxidation of 9-coordinated terrace sites. Oxidation to Pt-O species at potentials above 1.0 V are shown to correlate to the presence of growing surface roughness, and the simulations suggest the onset of Pt-O formation in steady-state cyclic voltammetry is dominated by the oxidation of 8-coordinated step edges rather than terrace sites. Implications for the stability of Pt(111) catalysts after thousands of voltammetric cycles are discussed.

PERBANDINGAN KAPASITAS VITAL PAKSA PARU PADA MAHASISWA PEROKOK DAN BUKAN PEROKOK DI FAKULTAS KEDOKTERAN UNIVERSITAS SAM RATULANGI MANADO

Indonesia is one of the countries with the highest smoking prevalence in the world. Tobacco is a major component of smoking may cause the death of half of its consumers. Cigarettes contain more than 4000 chemicals are exposed through cigarette smoke. Lung function as an exchange of oxygen and carbon dioxide into place exchange of substances contained in cigarettes, which would cause damage to the lungs. This study aimed to know the difference of Forced VitalCapacity (FVC) among students smokers and non-smokers in the Medical Faculty of Sam Ratulangi University. This was a cross sectional analytic survey (cross-sectional). The location was at Prodia Laboratory Manado. There were 40 samples ion this stiudy. The results showed that the value of p= 0.003 <α =0.05, and concluded that there were significant differences between students who smoked and who did not.Keywords: students smokers, students non-smokers, forced vital capacityAbstrak:Indonesia merupakan salah satu negara dengan angka prevalensi merokok tertinggi di dunia. Tembakau yang merupakan komponen utama rokok dapat menyebabkan kematian setengah dari penggunanya. Rokok mengandung lebih dari 4000 bahan kimia yang dipaparkan melalui asap rokok. Paru-paru yang berfungsi sebagai tempat pertukaran oksigen dengan karbon dioksida menjadi tempat pertukaran zat yang terkandung dalam rokok, yang akan menyebabkan teradinya kerusakan pada paru-paru. Tujuan dari penelitian ini yaitu mengetahui perbedaan Kapasitas Vital Paksa (KVP) pada Mahasiswa perokok dan bukan perokok di Fakultas Kedokteran Universitas Sam Ratulangi. Penelitian ini merupakan penelitian analitik. Desain penelitian yaitu cross sectional atau studi potong lintang, dimana pengukuran hanya dilakukan satu kali pada satu saat pada suatu populasi di wilayah tersebut. Lokasi penelitian dilakukan di Laboratorium Klinik Prodia Manado. Sampel pada penelitian ini berjumlah 40 orang. Hasil penelitian ini menunjukkan bahwa nilai p = 0.003 < α = 0,05, dan dapat disimpulkan bahwa terdapat perbedaan yang bermakna antara Mahasiswa perokok dan bukan perokok.Kata kunci: mahasiswa perokok, mahasiswa bukan perokok, kapasitas vital paksa paru

Differential reactivity of the inner and outer positions of Au25(SCH2CH2Ph)18 dimeric staples under place exchange conditions

The site selectivity of the place exchange reaction at the two inequivalent positions of the neutral Au25(SCH2CH2Ph)18 staples depends on the nature of the incoming thiol.