Synthesis and Characterization of Low Band Gap Small Molecules Based on Fluorine Substituted Benzothiadiazole for Photovoltaic Application

Sella Kurnia Putri,김윤환,김주현,장동욱 한국고분자학회 2016 한국고분자학회 학술대회 연구논문 초록집 Vol.41 No.1

Synthesis and Characterization of Benzodithiophene and Fluorinated Quinoxaline-Based Conjugated Polymers for Photovoltaic Application

Sella Kurnia Putri,김윤환,이민석,김주현,장동욱 한국고분자학회 2017 한국고분자학회 학술대회 연구논문 초록집 Vol.42 No.1

Fluorinated benzothiadiazole-based small molecules for photovoltaic applications

Putri, Sella Kurnia,Lee, Min Seok,Chang, Dong Wook,Kim, Joo Hyun Elsevier 2016 Synthetic metals Vol.220 No.-

<P><B>Abstract</B></P> <P>A series of medium band gap conjugated small molecules with a typical D-π-A-π-D structure, in which triphenylamine, thiophene, and benzothiadiazole are used as an electron-donor, a bridge, and an electron-acceptor, respectively, have been synthesized. To investigate the effects of strong electron-withdrawing fluorine atoms on various properties, one and two fluorine substituents are introduced to the central benzothiadiazole unit of N-(4-(5-(7-(5-(4-(diphenylamino)phenyl)thiophen-2-yl)benzo[c][1,2,5]thiadiazol-4-yl)thiophen-2-yl)phenyl)-N-phenylbenzenamine (<B>TPA-TBT</B>) to give <B>TPA-TBT-1F</B> and <B>TPA-TBT-2F</B>, respectively. Owing to the significant contributions of fluorine atoms, these small molecules exhibit clearly distinctive optical and electrochemical properties. Inverted-type organic photovoltaic cells (OPVs) with a configuration of ITO/ZnO/small molecules: PC<SUB>71</SUB>BM/MoO<SUB>3</SUB>/Al were fabricated and the fabricated cells showed maximum power conversion efficiencies of 0.84, 1.15 and 1.70% for <B>TPA-TBT</B>, <B>TPA-TBT-1F</B> and <B>TPA-TBT-2F</B>, respectively. The superior photovoltaic performance of <B>TPA-TBT-2F</B> is attributed to the relatively deep energy level of highest occupied molecular orbital (HOMO) and to more balanced electron- and hole-mobility within photoconversion layer. Therefore, this study can provide insights into the tuning the properties of benzothiadiazole-based small molecules by introducing fluorine substituents.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A series of medium band gap conjugated small molecules have been synthesized. </LI> <LI> Selective incorporation of fluorine atoms on the benzothiadiazole acceptors. </LI> <LI> Optical, electrochemical and photovoltaic properties have been investigated. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Structural Basis of Novel Iron-Uptake Route and Reaction Intermediates in Ferritins from Gram-Negative Bacteria

Kim, Sella,Lee, Ji-Hye,Seok, Jong Hyeon,Park, Yi-Ho,Jung, Sang Won,Cho, Art E.,Lee, Cheolju,Chung, Mi Sook,Kim, Kyung Hyun Elsevier 2016 Journal of molecular biology Vol.428 No.24

<P><B>Abstract</B></P> <P>Iron and oxygen chemistry is mediated by iron proteins for many biological functions. Carboxylate-bridged diiron enzymes including ferritin have the common mechanism of oxygen activation via peroxodiferric intermediates. However, the route for iron uptake and the structural identification of intermediates still remain incomplete. The 4-fold symmetry channel of <I>Helicobacter pylori</I> ferritin was previously proposed as the iron-uptake route in eubacteria, but the amino acid residues at the 4-fold channel are not highly conserved. Here, we show evidence for a short path for iron uptake from His93 on the surface to the ferroxidase center in <I>H. pylori</I> ferritin and <I>Escherichia coli</I> ferritin. The amino acid residues along this path are highly conserved in Gram-negative bacteria and some archaea, and the mutants containing S20A and H93L showed significantly decreased iron oxidation. Surprisingly, the <I>E. coli</I> ferritin S20A crystal structure showed oxygen binding and side-on, symmetric μ-η<SUP>2</SUP>:η<SUP>2</SUP> peroxodiferric and oxodiferric intermediates. The results provide the structural basis for understanding the chemical nature of intermediates in iron oxidation in bacteria and some of archaea.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Structural identification of intermediates in iron oxidation remains incomplete. </LI> <LI> A short, novel route for iron uptake in ferritins from bacteria is proposed. </LI> <LI> Mutants of residues along the route showed little iron oxidation activities. </LI> <LI> Peroxo- and oxodiferric intermediates were modeled in the mutant structure. </LI> <LI> Oxygen binding in this iron oxidation was also modeled in the structure. </LI> </UL> </P> <P><B>Graphical Abstract</B></P> <P>[DISPLAY OMISSION]</P>

Enhanced open-circuit voltages of trifluoromethylated quinoxaline-based polymer solar cells

Putri, Sella Kurnia,Jin, Ho Cheol,Whang, Dong Ryeol,Kim, Joo Hyun,Chang, Dong Wook Elsevier 2019 ORGANIC ELECTRONICS Vol.65 No.-

<P><B>Abstract</B></P> <P>Three quinoxaline-based conjugated polymers with donor-π-acceptor configurations have been synthesized by Stille coupling reaction. The electron-donating 2,3-dioctylthienyl- substituted benzodithiophene (BDT) unit was linked to the electron-accepting 2,3-diphenylquinoxaline (DPQ) group through a thiophene bridge, to produce a reference polymer <B>PTBDT-Qx</B>. Furthermore, the strong electron-withdrawing trifluoromethyl moieties were introduced at the <I>para</I>-position of the phenyl groups in the 2,3-positions of DPQ and 6,7-difluorinated DPQ, to afford <B>PTBDT-QxCF3</B> and <B>PTBDT-FQxCF3</B>, respectively. Owing to the continuous reduction in their HOMO energy levels with increasing number of electron-withdrawing groups, the open-circuit voltage (<I>V</I> <SUB>oc</SUB>) in polymer solar cells (PSCs) shows a gradual improvement in the order of <B>PTBDT-Qx</B> < <B>PTBDT-QxCF3</B> < <B>PTBDT-FQxCF3</B>. The inverted-type PSC based on <B>PTBDT-FQxCF3</B> with a configuration of ITO/ZnO/polymer:PC<SUB>71</SUB>BM/MoO<SUB>3</SUB>/Al provides the best power conversion efficiency of 6.47%, together with a <I>V</I> <SUB>oc</SUB> of 0.99 V, a short-circuit current of 10.03 mA/cm<SUP>2</SUP>, and a fill factor of 65.1%.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A series of conjugated polymers based on quinoxaline have been synthesized. </LI> <LI> Incorporation of trifluoromethyl group on the quinoxaline acceptors. </LI> <LI> Optical, electrochemical and photovoltaic properties have been investigated. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>A series of trifluoromethylated quinoxaline-based polymers were systematically synthesized by Stille coupling reaction. The results obtained in this study clearly reveal the significant contribution of the electron-withdrawing trifluoromethyl groups in enhancing the open-circuit voltages, as well as producing a sharp improvement in the power conversion efficiencies of polymer solar cells with bulk-heterojunction structure.</P> <P>[DISPLAY OMISSION]</P>

Soybean Molasses-based Bioindicator System for Monitoring Sterilization Process: Designing and Performance Evaluation

Sandra Regina B. R. Sella,Carla Masetti,Luis Felipe M. Figueiredo,Luciana P. S. Vandenberghe,João Carlos Minozzo,Carlos Ricardo Soccol 한국생물공학회 2013 Biotechnology and Bioprocess Engineering Vol.18 No.1

A novel cost-effective Bacillus atrophaeus Sterilization Bioindicator System (BIS) with a high quality and performance was developed from a soybean byproduct and compared with the commercial BIS. It was composed of recovery medium and dry-fermented spores with sand as the support. The BIS was developed and optimized using a sequential experimental design strategy. The recovery medium contained soluble starch (1.0 g/L),soybean molasses (30.0 g/L), tryptone (40.0 g/L), and bromothymol blue (0.02 g/L) at pH 8.5. The solid-state fermentation conditions of the bioreactor and environmental humidity had no significant effects on the spore yield and dry-heat resistance. The only substrate mineral that showed a positive effect was Mn2+, allowing Mg2+, K+, and Ca2+ to be eliminated from the formulation. Validation of optimized medium indicated D160°C = 6.8±1.0 min (3.6 min more than the minimum) and spore yield = 2.3 ± 0.5 × 109 CFU/g dry sand (10,000 × initial values). BIS performance resulted in D160°C = 6.6 ± 0.1 min. Sporulation and germination kinetics allowed the sporulation process to be reduced to three days, and the growth of heat-damaged spores was sufficient to achieve visual identification of a non-sterile BIS within 21 h. Process economics was a minimum of 23.9%, and process cycle time was reduced from 29 to 15days. The new BIS parameters demonstrated compliance to all regulatory requirements. No studies have yet described a BIS production from soybean molasses.

Synthesis of Quinoxaline-Based Small Molecules Possessing Multiple Electron-Withdrawing Moieties for Photovoltaic Applications

김준태,진호철,Sella Kurnia Putri,황동렬,김주현,장동욱 한국고분자학회 2019 Macromolecular Research Vol.27 No.12

Three quinoxaline-based small molecules possessing multiple electronwithdrawing moieties were synthesized by the Suzuki coupling reaction for organic photovoltaic cells (OPVs). The electron-donating triarylamine units were linked to both ends of electron-accepting 2,3-diphenyl quinoxaline (DPQ) derivatives with strong electron-withdrawing trifluoromethyl (CF3) moieties to produce a reference D-A-D type small molecule of CF3Qx-0F. Furthermore, one and two fluorine atoms were additionally introduced to the 6,7-positions of the DPQ unit of CF3Qx-0F affording CF3Qx-1F and CF3Qx-2F, respectively. Owing to the significant contribution of the electron-withdrawing CF3 and fluorine units, all invertedtype OPVs based on three small molecules exhibited high open circuit voltages greater than 0.82 V. In addition, the power conversion efficiencies (PCEs) of the devices were gradually improved with increasing number of fluorine atoms. The highest PCE (2.82%) with a V oc of 0.88 V, a short-circuit current of 6.38 mA cm-2, and a fill factor of 50.6% was achieved from the device based on CF3Qx-2F.

Single-shot regional anesthesia for laparoscopic cholecystectomies: a systematic review and network meta-analysis

De Cassai Alessandro,Sella Nicolò,Geraldini Federico,Tulgar Serkan,Ahiskalioglu Ali,Dost Burhan,Manfrin Silvia,Karapinar Yunus Emre,Paganini Greta,Beldagli Muzeyyen,Luoni Vittoria,Ordulu Busra Burcu K 대한마취통증의학회 2023 Korean Journal of Anesthesiology Vol.76 No.1

Background: Different regional anesthesia (RA) techniques have been used for laparoscopic cholecystectomy (LC), but there is no consensus on their comparative effectiveness. Our objective was to evaluate the effect of RA techniques on patients undergoing LC using a network meta-analysis approach.Methods: We conducted a systematic review and network meta-analysis. We searched PubMed, the Cochrane Central Register of Controlled Trials (CENTRAL), Scopus, and Web of Science (Science and Social Science Citation Index) using the following PICOS criteria: (P) adult patients undergoing LC; (I) any RA single-shot technique with injection of local anesthetics; (C) placebo or no intervention; (O) postoperative opioid consumption expressed as morphine milligram equivalents (MME), rest pain at 12 h and 24 h post-operation, postoperative nausea and vomiting (PONV), length of stay; and (S) randomized controlled trials.Results: A total of 84 studies were included. With the exception of the rectus sheath block (P = 0.301), the RA techniques were superior to placebo at reducing opioid consumption. Regarding postoperative pain, the transversus abdominis plane (TAP) block (−1.80 on an 11-point pain scale) and erector spinae plane (ESP) block (−1.33 on an 11-point pain scale) were the most effective at 12 and 24 h. The TAP block was also associated with the greatest reduction in PONV.Conclusions: RA techniques are effective at reducing intraoperative opioid use, postoperative pain, and PONV in patients undergoing LC. Patients benefit the most from the bilateral paravertebral, ESP, quadratus lumborum, and TAP blocks.

Preoperative dexmedetomidine and intraoperative bradycardia in laparoscopic cholecystectomy: a meta-analysis with trial sequential analysis

De Cassai Alessandro,Sella Nicolò,Geraldini Federico,Zarantonello Francesco,Pettenuzzo Tommaso,Pasin Laura,Iuzzolino Margherita,Rossini Nicolò,Pesenti Elisa,Zecchino Giovanni,Munari Marina,Navalesi Pa 대한마취통증의학회 2022 Korean Journal of Anesthesiology Vol.75 No.3

Background: While laparoscopic surgical procedures have various advantages over traditional open techniques, artificial pneumoperitoneum is associated with severe bradycardia and cardiac arrest. Dexmedetomidine, an imidazole derivative that selectively binds to α2-receptors and has sedative and analgesic properties, can cause hypotension and bradycardia. Our primary aim was to assess the association between dexmedetomidine use and intraoperative bradycardia during laparoscopic cholecystectomy. Methods: We performed a systematic review with a meta-analysis and trial sequential analysis using the following PICOS: adult patients undergoing endotracheal intubation for laparoscopic cholecystectomy (P); intravenous dexmedetomidine before tracheal intubation (I); no intervention or placebo administration (C); intraoperative bradycardia (primary outcome), intraoperative hypotension, hemodynamics at intubation (systolic blood pressure, mean arterial pressure, heart rate), dose needed for induction of anesthesia, total anesthesia requirements (both hypnotics and opioids) throughout the procedure, and percentage of patients requiring postoperative analgesics and experiencing postoperative nausea and vomiting and/or shivering (O); randomized controlled trials (S). Results: Fifteen studies were included in the meta-analysis (980 patients). Compared to patients that did not receive dexmedetomidine, those who did had a higher risk of developing intraoperative bradycardia (RR: 2.81, 95% CI [1.34, 5.91]) and hypotension (1.66 [0.92,2.98]); however, they required a lower dose of intraoperative anesthetics and had a lower incidence of postoperative nausea and vomiting. In the trial sequential analysis for bradycardia, the cumulative z-score crossed the monitoring boundary for harm at the tenth trial.Conclusions: Patients undergoing laparoscopic cholecystectomy who receive dexmedetomidine during tracheal intubation are more likely to develop intraoperative bradycardia and hypotension.

Public Key Encryption with Equality Test for Heterogeneous Systems in Cloud Computing

( Rashad Elhabob ),( Yanan Zhao ),( Iva Sella ),( Hu Xiong ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.9

Cloud computing provides a broad range of services like operating systems, hardware, software and resources. Availability of these services encourages data owners to outsource their intensive computations and massive data to the cloud. However, considering the untrusted nature of cloud server, it is essential to encrypt the data before outsourcing it to the cloud. Unfortunately, this leads to a challenge when it comes to providing search functionality for encrypted data located in the cloud. To address this challenge, this paper presents a public key encryption with equality test for heterogeneous systems (PKE-ET-HS). The PKE-ET-HS scheme simulates certificateless public encryption with equality test (CLE-ET) with the identity-based encryption with equality test (IBE-ET). This scheme provides the authorized cloud server the right to actuate the equivalence of two messages having their encryptions performed under heterogeneous systems. Basing on the random oracle model, we construct the security of our proposed scheme under the bilinear Diffie-Hellman (BDH) assumption. Eventually, we evaluate the size of storage, computation complexities, and properties with other related works and illustrations indicate good performance from our scheme.