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"A fluorescence spectrometer, with gating PMT (Photo Multiplier Tube) has been designed and constructed for the observation of Time Resolved Spectroscopy. Employed as a source far the fluorescence spectrometer a pulsed N2 lasers with about 5-nanosecond pulse width and 400-kilowatt power. Gating PMT carries out the sampling. In this method some of the dynodes of the PMT are being biased at voltages below normal operating voltage, while the other dynodes are held at their normal voltages. Sampling pulses generated by avalanche transistor are fed into the dynodes of the lower voltage to operate the PMT. A variable delay circuit of the order of nanosecond with respect to the N2 lasers pulse delays the sampling pulses. The output of the PMT is read on an oscilloscope and the lifetime of the fluorescence can be obtained by plotting the output of the PMT vs. the delay time."

"ABSTRAKSintesis ligan turunan pirazol 2-(1,5-difenil-4,5-dihidro-1H-pirazol-3-yl)piridin telah berhasil dilakukan dengan metode kondensasi Claisen-Schmidt diikuti dengan penambahan fenil hidrazin berlebih dalam medium pelarut etanol. Padatan kuning kemerahan dengan yield sebesar 28,85% kemudian dikarakterisasi menggunakan spektrofotometer UV-Vis, FTIR, dan spektrometer H-NMR. Studi spektroskopi UV-Vis dilakukan untuk mengetahui pembentukan kompleks antara logam lantanida dengan ligan dalam pelarut asetonitril. Uji aplikasi fluoresens dengan spektrofluorometer diamati untuk melihat perubahan intensitas emisi pada penambahan logam La3+ dan Eu3+. Hasil studi dengan spektroskopi UV-Visible menunjukkan pembentukan kompleks [EuL2]3+ dengan perbandingan Eu3+ : L (1:2) terjadi pada panjang gelombang 366 nm, sedangkan kompleks [LaL3]3+ dimana perbandingan La3+ : L (1:3) terjadi pada λmax 342 nm. Analisis fluoresensi menunjukkan ligan memiliki λ eksitasi 257 nm dan 365 nm dengan nilai absorptivitas molar yang cukup besar pada konsetrasi 2x10-5 M. Penambahan logam La3+ menghasilkan efek fluorescence enhancement pada panjang gelombang emisi 355 nm. Sedangkan penambahan Eu3+ menunjukkan efek pemadaman intensitas emisi pada panjang gelombang 340 nm. Studi selektivitas ligan terhadap keberadaan ion Eu3+ dan La3+ secara bersamaan menunjukkan ligan merupakan fluoresensor yang selektif terhadap La3+ pada λ eksitasi dan λ emisi 257 nm dan 356 nm serta terhadap Eu3+ pada λ eksitasi 273 nm dan λ emisi 341 nm

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ABSTRAKSynthesis of pyrazole derivative ligand 2- (1,5-diphenyl-4,5-dihydro-1H-pyrazole-3-yl) pyridine has been successfully carried out by the method of Claisen-Schmidt condensation followed by the excess addition of phenyl hydrazine in ethanol solution. Reddish yellow solid with a 28.85% yield then characterized using FTIR , UV-Visible, and H1-NMR spectroscopy. UV-Visible spectroscopy study was conducted to determine the complex formation between lanthanide ions with ligands. Fluorescence application test with spectrofluorometer was observed in ligand emission intensity change upon addition of La3+ and the Eu3+. The study by UV-Visible spectroscopy show complex formation of [EuL2]3+ with the ratio Eu3+ : L (1:2) occurs at a absorption wavelength of 366 nm, while the complex [LaL3]3+ with the ratio La3+ : L (1:2) occurred at 342 nm in acetonitrile solution. Fluorescence analysis showed ligands have two excitation λ at 257 nm 365 nm with a appreciable molar absorptivity in concentration 2x10-5 M. The addition of La3+ metal lead to the fluorescence enhancement effect on the λem at 355 nm. While the addition of the Eu3+ demonstrates the effect of fluorescence quenching at the λem 340 nm. Ligand selectivity studies of the existence of ion Eu3+ and La3+ simultaneously show selective fluorescence against La3+ occurred at λex and λem 257 nm and 356 nm as well as the Eu3+ occurred at 273 nm and 341 nm respectively."

"Risiko kegagalan dapat terjadi pada rekonstruksi dengan flap bebas karena mengandalkan vaskularisasi kecil. Pemeriksaan klinis yang merupakan baku emas dalam evaluasi sirkulasi flap masih bersifat subjektif dan sulit untuk mendeteksi gangguan vaskularisasi secara dini. Indocyanine green (ICG) merupakan instrumen pemeriksaan objektif yang dapat digunakan untuk evaluasi sirkulasi flap, tetapi belum ada konsensus mengenai dosis ICG dan kekuatan fluoresensi bersifat dose-dependent. Pada penelitian awal model in vitro dan hewan coba didapatkan konsentrasi 0,5 mg/mL menghasilkan fluoresensi yang setara dengan konsentrasi standar (5 mg/mL). Analisis dosis titrasi ICG dilakukan pada penelitian ini untuk mengevaluasi (sirkulasi) flap bebas menggunakan kamera near-infrared radiation standar serta korelasinya terhadap pemeriksaan suhu flap, TcPCO2, TcPO2, kadar HIF-1α, dan gambaran histopatologi flap untuk menunjang bedah mikro rekonstruksi. Penelitian menggunakan desain eksperimental uji klinis acak tersamar ganda di Rumah Sakit Umum Pusat Nasional dr. Cipto Mangunkusumo (RSCM) dan Rumah Sakit Persahabatan (RSP) pada bulan September 2022 hingga Januari 2024. Sebanyak 63 pasien yang sesuai dengan kriteria inklusi dari kuesioner skrining dilakukan randomisasi menjadi 3 kelompok konsentrasi ICG, yaitu 5 mg/mL, 2,5 mg/mL, dan 0,5 mg/mL yang diberikan ICG secara intravena, dengan jumlah masing-masing 21 flap. Data diambil segera pasca-operasi, 24 jam, 72 jam, serta 120 jam pasca-operasi. Ketiga kelompok menunjukkan peningkatan fluoresensi ICG dari waktu ke waktu, dengan intensitas fluoresensi pada konsentrasi 2,5 mg/mL serupa dengan konsentrasi standar (p = 0,792), tetapi intensitas konsentrasi 0,5 mg/mL lebih lemah (p = 0,006 dan p = 0,041). Intensitas fluoresensi tidak berkorelasi dengan pemeriksaan objektif lainnya. Disimpulkan besar dosis ICG memengaruhi intensitas fluoresensi karena fenomena quenching effect dan keseimbangan ikatan ICG dengan protein plasma. Analisis konsentrasi 5 mg/mL dan 2,5 mg/mL menghasilkan intensitas serupa sehingga penggunaan dosis 2,5 mg/mL dapat menggantikan dosis standar pada praktik klinis. Pemeriksaan objektif lainnya belum dapat menggantikan pemeriksaan ICG untuk evaluasi sirkulasi flap bebas.

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The risk of failure in free flap reconstruction may occur due to small vascularization. Clinical examination, which is the gold standard for free flap evaluation, is subjective and difficult to detect early vascularization problems. Indocyanine green (ICG) is an objective instrument to evaluate flap circulation, but there is no ICG consensus and the fluorescence emitted is dose-dependent. In the preliminary studies conducted in vitro followed by in vivo with animal models, we found that 0.5 mg/mL concentration produced equivalent fluorescence to the standard concentration (5 mg/mL). This study aimed to analyze the titration dose of ICG to evaluate free flaps using a standard near-infrared radiation camera and its correlation with the examination of flap temperature, TcPCO2, TcPO2, HIF-1α levels, and histopathological to support reconstructive microsurgery procedure. This was a randomized, double-blind clinical trial at Dr. Cipto Mangunkusumo National Central General Hospital and Persahabatan Hospital from September 2022 to January 2024. A total of 63 patients that met the inclusion criteria through screening questionnaire were randomized into 3 ICG concentration groups: 5 mg/mL, 2.5 mg/mL, and 0.5 mg/mL. The ICG was given intravenously to each group which consist of 21 subjects. The data were obtained immediately postoperative, 24 hours, 72 hours, and 120 hours post-operative. There were 63 flaps divided into three groups with 21 flaps each. All three groups showed an increase in ICG fluorescence over time, with fluorescence intensity emitted by 2.5 mg/mL concentration is equivalent to the standard concentration (p = 0.792), but the fluorescence from 0.5 mg/mL concentration emitted weaker intensity (p = 0.006 and p = 0.041). Fluorescence intensity did not correlate with other objective examinations. It was concluded that the titration dose of ICG influenced the fluorescence intensity due to quenching effect and ICG and plasma protein bond equilibrium. Analysis of 5 mg/mL and 2.5 mg/mL concentration groups produced similar intensities, leading to the feasibility of 2.5 mg/mL concentration to replace the standard dose in clinical practice. Other objective examinations can not replace ICG examination for free flap perfusion evaluation."