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1.
Luminescence ; 39(7): e4823, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38965884

RESUMO

A highly selective bis thiophene-based chalcone as a chemosensor for detecting Fe3+ metal ions in DMF: H2O (9:1). This sensor was selective toward ferric ions over other metal ions with a detection limit in micromolar range.


Assuntos
Espectrometria de Fluorescência , Tiofenos , Tiofenos/química , Ferro/análise , Ferro/química , Estrutura Molecular , Compostos Férricos/química , Compostos Férricos/análise , Chalconas/química , Chalconas/análise , Chalcona/química , Corantes Fluorescentes/química
2.
Chemistry ; 27(7): 2348-2360, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33175428

RESUMO

The structures of proton-bound complexes of 5,7-dimethoxy-4H-chromen-4-one (1) and basic amino acids (AAs), namely, histidine (His) and lysine (Lys), have been examined by means of mass spectrometry coupled with IR ion spectroscopy and quantum chemical calculations. This selection of systems is based on the fact that 1 represents a portion of glabrescione B, a natural small molecule of promising antitumor activity, while His and Lys are protein residues lining the cavity of the alleged receptor binding site. These species are thus a model of the bioactive adduct, although clearly the isolated state of the present study bears little resemblance to the complex biological environment. A common feature of [1+AA+H]+ complexes is the presence of a protonated AA bound to neutral 1, in spite of the fact that the gas-phase basicity of 1 is comparable to those of Lys and His. The carbonyl group of 1 acts as a powerful hydrogen-bond acceptor. Within [1+AA+H]+ the side-chain substituents (imidazole group for His and terminal amino group for Lys) present comparable basic properties to those of the α-amino group, taking part to a cooperative hydrogen-bond network. Structural assignment, relying on the comparative analysis of the infrared multiple photon dissociation (IRMPD) spectrum and calculated IR spectra for the candidate geometries, derives from an examination over two frequency ranges: 900-1800 and 2900-3700 cm-1 . Information gained from the latter one proved especially valuable, for example, pointing to the contribution of species characterized by an unperturbed carboxylic OH or imidazole NH stretching mode.


Assuntos
Aminoácidos/química , Antineoplásicos/química , Espectrofotometria Infravermelho , Ligação de Hidrogênio , Fótons , Prótons , Vibração
3.
Annu Rev Phys Chem ; 71: 189-211, 2020 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-32070214

RESUMO

The gas-phase ground-state dissociation energy D0(S0) of an isolated and cold bimolecular complex is a fundamental measure of the intermolecular interaction strength between its constituents. Accurate D0 values are important for the understanding of intermolecular bonding, for benchmarking high-level theoretical calculations, and for the parameterization of dispersion-corrected density functionals or force-field models that are used in fields ranging from crystallography to biochemistry. We review experimental measurements of the gas-phase D0(S0) and D0(S1) values of 55 different M⋅S complexes, where M is a (hetero)aromatic molecule and S is a closed-shell solvent atom or molecule. The experiments employ the triply resonant SEP-R2PI laser method, which involves M-centered (S0 → S1) electronic excitation, followed by S1 → S0 stimulated emission spanning a range of S0 state vibrational levels. At sufficiently high vibrational energy, vibrational predissociation of the M⋅S complex occurs. A total of 49 dissociation energies were bracketed to within ≤1.0 kJ/mol, providing a large experimental database of accurate noncovalent interactions.

4.
J Chem Phys ; 152(10): 104304, 2020 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-32171216

RESUMO

The ground-state intermolecular dissociation energies D0(S0) of supersonic-jet cooled intermolecular complexes of 1-naphthol (1NpOH) with the bi- and tricycloalkanes trans-decalin, cis-decalin, and adamantane were measured using the stimulated-emission-pumping/resonant two-photon ionization (SEP-R2PI) method. Using UV/UV holeburning, we identified two isomers (A and B) of the adamantane and trans-decalin complexes and four isomers (A-D) of the cis-decalin complex. For 1NpOH·adamantane A and B, the D0(S0) values are 21.6 ± 0.15 kJ/mol and 21.2 ± 0.32 kJ/mol, those of 1NpOH·trans-decalin A and B are 28.7 ± 0.3 kJ/mol and 28.1 ± 0.9 kJ/mol, and those of 1NpOH·cis-decalin A and B are 28.9 ± 0.15 kJ/mol and 28.7 ± 0.3 kJ/mol. Upon S0 → S1 electronic excitation of the 1NpOH moiety, the dissociation energies of adamantane, trans-decalin, and the cis-decalin isomer C change by <1% and those of cis-decalin isomers A, B, and D increase only slightly (1%-3%). This implies that the hydrocarbons are dispersively adsorbed to a naphthalene "face." Calculations using the dispersion-corrected density functional theory methods B97-D3 and B3LYP-D3 indeed predict that the stable structures have face geometries. The B97-D3 calculated D0(S0) values are within 1 kJ/mol of the experiment, while B3LYP-D3 predicts D0 values that are 1.4-3.3 kJ/mol larger. Although adamantane has been recommended as a "dispersion-energy donor," the binding energies of the trans- and cis-decalin adducts to 1NpOH are 30% larger than that of adamantane. In fact, the D0 value of 1NpOH·adamantane is close to that of 1NpOH·cyclohexane, reflecting the nearly identical contact layer between the two molecules.

5.
J Chem Phys ; 150(23): 234303, 2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31228890

RESUMO

The stimulated-emission-pumping/resonant 2-photon ionization (SEP-R2PI) method was used to determine the intermolecular dissociation energies D0 of jet-cooled 1-naphthol(1NpOH)·S complexes, where S is a linear molecule (N2, CO, CO2, OCS, N2O, and ethyne) or symmetric-top molecule (2-butyne) that contains double or triple bonds. The dissociation energies D0(S0) are bracketed as follows: 6.68 ± 0.08 kJ/mol for S=N2, 7.7 ± 0.8 kJ/mol for CO, 12.07 ± 0.10 kJ/mol for CO2, 13.03 ± 0.01 kJ/mol for N2O, 14.34 ± 0.08 kJ/mol for ethyne, 15.0 ± 1.35 kJ/mol for OCS, and 29.6 ± 2.4 kJ/mol for 2-butyne. The minimum-energy structures, vibrational wavenumbers, and zero-point vibrational energies were calculated using the dispersion-corrected density functional theory methods such as B97-D3 and B3LYP-D3 with the def2-QZVPP basis set. These predict that N2 and CO are dispersively bound Face complexes (S bound to a naphthalene Face), while CO2, N2O, and OCS adsorb into the "Notch" between the naphthyl and OH groups; these are denoted as Notch complexes. Ethyne and 2-butyne form Edge complexes involving H-bonds from the -OH group of 1NpOH to the center of the molecule. The presence of a double or triple bond or an aromatic C=C bond within S does not lead to a specific calculated geometry (Face, Notch or Edge). However, a correlation exists between the structure and the sign of the quadrupole moment component Θzz of S: negative Θzz correlates with Face or Notch, while positive Θzz correlates with Edge geometries.

6.
J Chem Phys ; 148(13): 134302, 2018 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-29626863

RESUMO

We measured accurate intermolecular dissociation energies D0 of the supersonic jet-cooled complexes of 1-naphthol (1NpOH) with the noble gases Ne, Ar, Kr, and Xe and with N2, using the stimulated-emission pumping resonant two-photon ionization method. The ground-state values D0(S0) for the 1NpOH⋅S complexes with S= Ar, Kr, Xe, and N2 were bracketed to be within ±3.5%; they are 5.67 ± 0.05 kJ/mol for S = Ar, 7.34 ± 0.07 kJ/mol for S = Kr, 10.8 ± 0.28 kJ/mol for S = Xe, 6.67 ± 0.08 kJ/mol for isomer 1 of the 1NpOH⋅N2 complex, and 6.62 ± 0.22 kJ/mol for the corresponding isomer 2. For S = Ne, the upper limit is D0 < 3.36 kJ/mol. The dissociation energies increase by 1%-5% upon S0 → S1 excitation of the complexes. Three dispersion-corrected density functional theory (DFT-D) methods (B97-D3, B3LYP-D3, and ωB97X-D) predict that the most stable form of these complexes involves dispersive binding to the naphthalene "face." A more weakly bound edge isomer is predicted in which the S moiety is H-bonded to the OH group of 1NpOH; however, no edge isomers were observed experimentally. The B97-D3 calculated dissociation energies D0(S0) of the face complexes with Ar, Kr, and N2 agree with the experimental values within <5%, but the D0(S0) for Xe is 12% too low. The B3LYP-D3 and ωB97X-D calculated D0(S0) values exhibit larger deviations to both larger and smaller dissociation energies. For comparison to 1-naphthol, we calculated the D0(S0) of the carbazole complexes with S = Ne, Ar, Kr, Xe, and N2 using the same DFT-D methods. The respective experimental values have been previously determined to be within <2%. Again, the B97-D3 results are in the best overall agreement with experiment.

7.
J Chem Phys ; 149(20): 204311, 2018 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-30501267

RESUMO

We have measured the intermolecular dissociation energies D 0 of supersonically cooled 1-naphthol (1NpOH) complexes with solvents S = furan, thiophene, 2,5-dimethylfuran, and tetrahydrofuran. The naphthol OH forms non-classical H-bonds with the aromatic π-electrons of furan, thiophene, and 2,5-dimethylfuran and a classical H-bond with the tetrahydrofuran O atom. Using the stimulated-emission pumping resonant two-photon ionization method, the ground-state D 0(S 0) values were bracketed as 21.8 ± 0.3 kJ/mol for furan, 26.6 ± 0.6 kJ/mol for thiophene, 36.5 ± 2.3 kJ/mol for 2,5-dimethylfuran, and 37.6 ± 1.3 kJ/mol for tetrahydrofuran. The dispersion-corrected density functional theory methods B97-D3, B3LYP-D3 (using the def2-TZVPP basis set), and ωB97X-D [using the 6-311++G(d,p) basis set] predict that the H-bonded (edge) isomers are more stable than the face isomers bound by dispersion; experimentally, we only observe edge isomers. We compare the calculated and experimental D 0 values and extend the comparison to the previously measured 1NpOH complexes with cyclopropane, benzene, water, alcohols, and cyclic ethers. The dissociation energies of the nonclassically H-bonded complexes increase roughly linearly with the average polarizability of the solvent, α ¯ (S). By contrast, the D 0 values of the classically H-bonded complexes are larger, increase more rapidly at low α ¯ (S), but saturate for large α ¯ (S). The calculated D 0(S 0) values for the cyclopropane, benzene, furan, and tetrahydrofuran complexes agree with experiment to within 1 kJ/mol and those of thiophene and 2,5-dimethylfuran are ∼3 kJ/mol smaller than experiment. The B3LYP-D3 calculated D 0 values exhibit the lowest mean absolute deviation (MAD) relative to experiment (MAD = 1.7 kJ/mol), and the B97-D3 and ωB97X-D MADs are 2.2 and 2.6 kJ/mol, respectively.

8.
J Minim Access Surg ; 13(2): 118-123, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28281475

RESUMO

Context and Aims: Our study aims to evaluate the post-operative pain and cosmesis of single-incision laparoscopic cholecystectomy (SILC) in comparison with the standard, 3-port laparoscopic cholecystectomy (SLC) with respect to the length of incision, cosmetic scores, post-operative pain scores and duration of hospital stay. SETTINGS AND DESIGN: This comparative randomised study was conducted in a tertiary care centre teaching hospital between September 2012 and 2014. One hundred and fifty consecutive patients, who qualified as per inclusion criteria, were included in the study. SUBJECTS AND METHODS: Seventy-five patients were included in the SLC arm and 75 in the SILC arm. SILC procedure was carried out as transumbilical multiport technique and SLC as 3-port technique utilizing - 5, 5, 10 mm ports. STATISTICAL ANALYSIS USED: The data for the primary observations (post-operative pain scores, cosmetic score and incision length) and secondary observation (post-operative hospital stay) were noted. Weighted mean difference was used for calculation of quantitative variables, and odds ratios were used for pooling qualitative variables. RESULTS: Pain scores at 4 and 24 h were significantly better for SILC arm than SLC arm (at 4 h - 4.84 ± 0.95 vs. 6.17 ± 0.98, P < 0.05 and at 24 h - 3.84 ± 0.96 vs. 5.17 ± 0.09, P < 0.05). Length of incision was significantly smaller (SILC - 2.631 ± 0.44 cm vs. SLC - 5.11 ± 0.44 cm), P < 0.05 and cosmetic score was significantly better in SILC arm (6.25 ± 1.24) than SLC arm (4.71 ± 1.04), P < 0.05. Difference between the hospital stay is insignificant for two arms SILC (2.12 ± 0.34) and SLC (2.13 ± 0.35), P > 0.05. DISCUSSION: Significant difference was found in duration and intensity of pain between two procedures at 4 and 24 h. Cosmesis was significantly better in SILC than SLC group, the sample size in our study was small to arrive at a definite conclusion. The procedure can be selectively and judiciously performed by surgeons trained in regular laparoscopic surgery. Furthermore, the threshold for conversion should be low in learning phase. Widespread application must await Level 1 evidence from prospective trials.

10.
J Minim Access Surg ; 11(2): 134-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25883454

RESUMO

BACKGROUND: Single incision laparoscopic surgery, especially transumbilical, should be the closest to replicate the minimal access results achieved by natural orifice endoscopic surgery (NOTES). This study of single incision transabdominal preperitoneal (SITAPP) inguinal hernia repair is a continuing study exploring the peroperative variables and short and long term complications of this procedure. PATIENTS AND METHODS: All the 183 patients were operated by the same surgeon through a horizontal transumbilical incision positioned across the lower third of the umbilicus. Port access was through three separate transfacial punctures. Routine rigid instruments were used and the peritoneal flaps were either tacked or sutured into place. Patients with irreducible hernia and obstructed hernia were included, while those with strangulated hernia were excluded. RESULTS: All the patients were male with an average age of 41.4 years. Twenty four patients had bilateral hernia, 15 patients had irreducible and 6 patients had obstructed hernia. The mean operating time was 38.3 mins for unilateral hernias completed with tackers and 42.8 mins in those with intracorporeal suturing. The corresponding operating time for bilateral hernias was 53.2 and 62.7 minutes. There was minimal serous discharge from the umbilicus in 8 patients, port site infection in 1 patient and recurrence in 2 patients over a 36 months period. CONCLUSIONS: SITAPP for groin hernias, performed with conventional instruments is feasible, easy to learn, has a very high patient acceptance and is cosmetically superior to conventional TAPP. The use of tackers reduces the operating time significantly.

11.
J Minim Access Surg ; 10(4): 175-9, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25336816

RESUMO

INTRODUCTION: The feasibility of the single incision, multiport transumbilical approach(SILC) for the treatment of symptomatic gallbladder calculus disease has been established. AIMS: The study examines both short and long term morbidity of the SILC approach. MATERIALS AND METHODS: All the 1338 patients were operated by the same surgeon through a transversely placed umbilical incision in the upper third of the umbilicus. Three conventional ports,10,5 and 5 mm were introduced through the same skin incision but through separate transfascial punctures. The instruments were those used for standard laparoscopic cholecystectomy(SLC).Patients with acute cholecystitis and calculous pancreatitis were included,while those with choledocholithiasis were excluded. Results were compared with those of SLC. RESULTS: Forty patients had difficult gall bladders, 214 had acute cholecystitis, and 16 had calculous pancreatitis. The mean operating time was 24.7 mins as compared to 18.4 mins in SLC. Intracorporeal knotting was required in four patients. Conversion to SLC was required in 12 patients. Morrisons pouch drain was left in 3 patients. Injectable analgesics were required in 85% vs 90% (SILC vs SLC) on day 1 and 25% vs 45% on day 2 and infection was seen in 6(0. 45%) patients. Port site hernia was seen in 2 patients. The data was compared with that of SLC and significance calculated by the student 't' test. A p value less than 0.05 was considered as significant. CONCLUSIONS: Trans umbilical SILC gives comparable results to SLC, and is a superior alternative when cosmesis and postoperative pain are considered, but the operative time is significantly more.

12.
Small Methods ; 8(1): e2301086, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37806766

RESUMO

A transportable reversible assembly of gold nanoparticles (AuNPs) in an aqueous environment addresses the need for in situ surafce-enhanced Raman spectroscopy (SERS) hotspot creation for biological applications. Usually, light-directed AuNP assembly methods use higher laser powers and surfactants and are, hence, unsuitable for biological applications. Here, surface plasmon polaritons-assisted dynamic assembly of AuNPs are demonstrated at laser power density as low as 100 nW µm-2 . The AuNP assembly with multiple controllable hotspots is generated in an Au-water interface for solution-based SERS measurements. The major advantage of the method is that the interparticle nanogap is tunable to achieve analyte and AuNP-specific optimum SERS enhancement. The SERS intensity is reproducible on multiple reassembly cycles and assembly attempts, proving repeatability in the produced nanogap pattern. The assembly experiments reveal the influence of AuNP surface charge and the resulting polarizability on the SPP forces. The developed system and method can detect sulforhodamine 101 (SR101) dye molecules at concentrations as low as 10-10  m. Further, the SERS measurements on double-stranded DNA suggest that the molecules are oriented in a fashion to expose adenosine to the enhanced field, leading to its dominance in the recorded spectra.

13.
RSC Adv ; 14(28): 20398-20409, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38932983

RESUMO

Synthesis of new supramolecules with specific properties and realistic applications requires a sound knowledge of the structure-property relationships of the synthesized molecules. Non-covalent interaction like hydrogen bonding is conducive in realizing mesomorphism. The induction of the liquid crystalline character is associated with the strength of hydrogen bonds formed between the interacting components, which are affected by the change of polarity and polarizability of both components upon change in their terminal polar substituents. When the polar substituents are similar in their reactivity, how does the size of the polar substituent influence the mesomorphism? New hydrogen bonded liquid crystals are synthesized with fluorine and chlorine as substituents, and the mesomorphic behaviour is studied with the size of the substituent as a critical parameter. The chemical characterization is carried out by FTIR measurements, the phase characterization by polarizing optical microscopy and the thermal characterization by differential scanning calorimetry. The DFT method utilizing wb97x-D theory along with the cc-pVTZ basis set were used for the calculations. The hybrid functional B3LYP-D3 and Gaussian type basis set 6-31G(d,p) were used for studying the orientation of the molecules. It is observed that the ortho substituents reduce the co-planarity, meta substituents lead to the molecular broadening while para substituents exhibited highest mesomorphism by enhancing longitudinal dipole moment. Fluoro substituted compounds are exhibiting higher mesomorphism while the bulky chloro substituents are helping to better stack the molecules possessing longer chain lengths.

16.
JSLS ; 27(2)2023.
Artigo em Inglês | MEDLINE | ID: mdl-37187807

RESUMO

Background: Excruciating generalized abdominal pain with features suggestive of shock, at the end of the first or early second week after laparoscopic cholecystectomy (LC), is a frightening and formidable diagnostic predicament. This is because the early known complications like biliary leak or vascular injuries are unlikely diagnoses. Hemoperitoneum, is not usually considered, but instead more common occurrences like acute pancreatitis, choledocholithiasis, and sepsis are suspected. A delay in diagnosis and subsequent management of hemoperitoneum could have disastrous consequences. Case Studies: Two patients presented with hemoperitoneum, in the second week after laparoscopic cholecystectomy. The first was because of a leak from a pseudoaneurysm of the right hepatic artery and the other was a bleed from a subcapsular liver hemangioma as a part of Osler Weber Rendu syndrome. Initially, a clinical assessment in both the patients was diagnostically inconclusive. Ultimately the diagnosis could be made, based on computed tomography angiography and visceral angiography. In the second patient, a positive family history and genetic testing were helpful. The first patient was successfully managed by intravascular embolization, while the second patient was successfully managed conservatively with intraperitoneal drains and conservative management of comorbidities. Conclusions: The presentation is to generate awareness that hemorrhage could be a presentation, in the early second week, after LC. A common cause to be considered is a pseudo aneurysmal bleed. Secondary hemorrhage and other rare coincidental unassociated conditions could also be responsible for the hemorrhage. A high index of suspicion, and early and timely management are keys to a successful outcome.


Assuntos
Colecistectomia Laparoscópica , Embolização Terapêutica , Pancreatite , Humanos , Colecistectomia Laparoscópica/efeitos adversos , Hemoperitônio/diagnóstico , Hemoperitônio/etiologia , Hemoperitônio/terapia , Doença Aguda , Pancreatite/etiologia , Embolização Terapêutica/métodos
17.
JSLS ; 27(2)2023.
Artigo em Inglês | MEDLINE | ID: mdl-37187806

RESUMO

Background and Objectives: Laparoscopic inguinal hernia repair (LIHR) includes transabdominal preperitoneal repair (TAPP), standard totally extraperitoneal repair (TEP), and now extended TEP (eTEP). However, there is still a paucity of well conducted, peer reviewed comparative studies regarding the advantages, if any, of eTEP. This study aimed to compare the data of eTEP repair with that of TEP and TAPP repair. Methods: Two hundred twenty patients were randomly assigned to one of three groups of eTEP (80), TEP (68), and TAPP (72) after matching for age, sex, and clinical extent of hernia. Permission of ethics committee was taken. Results: Comparison with TEP showed, mean operating time for eTEP was significantly longer in the first 20 patients, subsequently there was no difference. Conversion rates of TEP to TAPP was significantly higher. The other peroperative and postoperative parameters did not differ. Similarly, on comparison with TAPP, there was no difference in any of the parameters. eTEP, also had shorter operating time and less incidence of pneumoperitoneum when compared to published TEP and TAPP studies. Conclusion: All the three laparoscopic hernia approaches had similar outcomes. eTEP cannot be advocated as a substitute for TAPP or TEP.The choice of procedure should be the surgeon's choice. However, eTEP does combine the advantage of both TAPP, in the form of a large working space and of TEP, by being totally extraperitoneal. eTEP is also easier to learn and teach.


Assuntos
Hérnia Inguinal , Laparoscopia , Humanos , Laparoscopia/métodos , Hérnia Inguinal/cirurgia , Herniorrafia/métodos , Resultado do Tratamento , Telas Cirúrgicas
18.
JSLS ; 27(4)2023.
Artigo em Inglês | MEDLINE | ID: mdl-38045818

RESUMO

Background and Objectives: Modified anterior preperitoneal (mAPP) repair for inguinal hernia (IH) was compared with Lichtenstein repair (LR) and laparoscopic transabdominal preperitoneal (TAPP) repairs. Methods: IH patients, after exclusions and subsequent matching for age, type, and extent of hernia, were assigned randomly for mAPP, LR or TAPP repair. The same surgical team performed all operations. Data of predefined endpoints for all the three groups were statistically compared. Results: One hundred thirty-five patients underwent mAPP, 91 patients LR, and 181 patients TAPP. The operating time for both unilateral and bilateral hernias in the mAPP group was significantly shorter than in LR and TAPP groups. mAPP patients were discharged in significantly less time than LR patients but later than TAPP patients. Postoperative visual analog scale (VAS) score at 24 hours in the mAPP patients was significantly less than LR but at 48 hours the difference was equivocal. But VAS score after mAPP at 24 and 48 hrs was more than in TAPP patients. However, the pain score across all the three groups was similar at 7 days. There was no surgical site infection (SSI) or mesh infection in any patient. Chronic postoperative inguinal pain was seen less often after mAPP than after LR but was least in TAPP patients. Recurrence across all the three groups was not much different. Conclusion: mAPP appears to be a better choice for open IH repair than LR and matches the advantages of Laparoscopic repairs.


Assuntos
Hérnia Inguinal , Laparoscopia , Humanos , Resultado do Tratamento , Telas Cirúrgicas , Hérnia Inguinal/cirurgia , Dor Pós-Operatória/epidemiologia , Herniorrafia , Recidiva
19.
Heliyon ; 9(10): e21014, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37916072

RESUMO

6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole. HCl (FPBH), a substituted benzisoxazole derivative, was prepared from isonipecotic acid and characterized using various spectroscopic techniques. Using electrochemical examinations such as potentiodynamic polarisation (PDP) and electrochemical impedance spectroscopic (EIS) technique, the corrosion mitigation capabilities of this compound for mild steel (MS) in 0.5 M HCl medium were investigated. Theoretical studies were performed using quantum chemical calculations and density functional theory (DFT). PDP results exhibited the mixed-type behavior of FPBH and showed a maximum efficiency of 94.5 % at 1 × 10-3 M. The development of a protective adsorbed layer of FPBH decreases the corrosion current density (icorr) and corrosion rate (CR). The EIS technique revealed that the rise in the charge transfer resistance (Rct) values and reduction in the thickness of the double-layer capacitance (Cdl) reflected the drop in corrosion rate. The adsorption of FPBH took place through physisorption by conforming Langmuir's isotherm. The DFT method was performed on the optimized structure of FPBH to get additional evidence on the action mode of FPBH with the metal surface.

20.
Exp Clin Transplant ; 21(8): 701-704, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37698404

RESUMO

Auxiliary partial orthotopic liver transplant is a complex technique whereby a partial liver graft is transplanted in the orthotopic position, leaving behind a portion of the native liver. In acute liver failure, auxiliary partial orthotopic liver transplant serves as a rescue therapy and bridge for the native liver to regenerate. Auxiliary partial orthotopic liver transplant was initially considered a technically challenging procedure with inferior results versus orthotopic liver transplant. However, advancements in surgical techniques have led to improved results with auxiliary partial orthotopic liver transplant. Auxiliary partial orthotopic liver transplant is now increasingly accepted as a valid treatment option for acute liver failure. We present 2 cases of acute liver failure treated with auxiliary partial orthotopic liver transplant using an extra-small-for-size graft. The first case was a 12-year-old female patient who presented with druginduced acute liver failure and required an auxiliary partial orthotopic liver transplant with an extra-small left lobe graft (graft-to-recipient weight ratio of 0.45). The second case was a 23-year-old male patient with acute liver failure of unknown etiology who underwent an auxiliary partial orthotopic liver transplant with a small right lobe graft (graft-torecipient weight ratio of 0.5). In both cases, computed tomography liver volumetry was performed to determine the appropriate graft size for the recipient. Both patients underwent successful auxiliary partial orthotopic liver transplants, with good postoperative recovery. Follow-up examinations showed satisfactory liver function without evidence of graft failure or rejection. Auxiliary partial orthotopic liver transplant using extra-small grafts can be an effective treatment option for acute liver failure when no other suitable option exists, including as a rescue procedure for small grafts. However, careful patient selection and surgical planning are essential to ensure successful outcomes.


Assuntos
Falência Hepática Aguda , Transplante de Fígado , Transplantes , Feminino , Masculino , Humanos , Criança , Adulto Jovem , Adulto , Transplante de Fígado/efeitos adversos , Falência Hepática Aguda/diagnóstico , Falência Hepática Aguda/etiologia , Falência Hepática Aguda/cirurgia , Seleção de Pacientes
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