The Effects of Different Methods of Anaesthesia for Laparoscopic Radical Gastrectomy with Monitoring of Entropy.

AIM: To investigate the effects of methods of total intravenous anaesthesia (TIVA) and combined intravenous and inhaled anaesthesia (CIIA) for laparoscopic radical gastrectomy under the same anaesthetic depth monitored by entropy indices. PATIENTS AND METHODS: One hundred patients undergoing laparoscopic radical gastrectomy were randomly distributed into group I (anaesthetized by TIVA) and group II (anaesthetized by CIIA), each group including 50 patients. TIVA was performed with propofol and remifentanil by means of target controlled infusion (TCI) for the patients in group I. CIIA was performed for patients in group II by inhalation of sevoflurane and continuous infusion of remifentanil after anaesthesia induction, with state entropy (SE) maintained in the range of 45-60 and difference regarding response entropy (RE) and SE less than 10.3. The concentrations of epinephrine, norepinephrine and dopamine in plasma from radial artery blood samples were measured and the durations of surgical operation, breathing recovery, extubation, awakening, and postoperative orientation recovery recorded; and 48 h postoperative adverse reactions at the following times: the time at which the patient becomes calm for 5 min after entering the operating theatre (T0); upon completion of pneumoperitoneum (PPT) (T1); 15 min after PPT (T2); intraoperative detection (T3), immediately after extubation (T4); and 15 min after extubation (T5). RESULTS: Comparing the measurements of epinephrine, norepinephrine and dopamine in plasma of the above two groups at the same time, the difference between the measurements at T0 and T2, and T5 were not statistically significant (p>0.05), whereas those at T1, T3, and T4 were statistically significant (p<0.05). Specifically, the measurements for group I were significantly higher than those for group II; the differences regarding the duration of breathing recovery, extubation, and awakening in both groups were not statistically significant (p>0.05). The postoperative orientation recovery duration for group II was significantly less than that that for group I (p<0.05); none of the patients in either group had intraoperative awareness, and the incidence of adverse reactions, such as nausea, vomit, and agitation in both groups was not statistically significantly different (p>0.05). CONCLUSION: At the same anaesthetic depth, the CIIA method outperforms the TIVA method in suppressing the stress response and obtaining smooth awakening after laparoscopic radical gastrectomy for patients with gastric cancer; therefore, the CIIA method has a better anaesthetic effect.

Synthesis of semiconducting polymer microparticles as solid ionophore with abundant complexing sites for long-life Pb(II) sensors.

Intrinsically electrically semiconducting microparticles of semiladder poly(m-phenylenediamine-co-2-hydroxy-5-sulfonic aniline) structures containing abundant functional groups, like -NH-, -N=, -NH2, -OH, -SO3H as complexation sites, were efficiently synthesized by chemical oxidative copolymerization of m-phenylenediamine and 2-hydroxy-5-sulfonic aniline. The obtained copolymers were found to be nonporous spherical microparticles that were able to achieve greater π-conjugated structure, smaller particle aggregate size, and stronger interaction with Pb(II) ions than poly(m-phenylenediamine) containing only -NH-, -N=, and -NH2. A potentiometric Pb(II) sensor was fabricated on the basis of the copolymer microparticles as a crucial solid ionophore component within plasticized PVC. The sensor exhibited a Nernstian response to Pb(II) ions over a wide concentration range, together with a fast response, a wide pH range capability, a long lifetime of up to 5 months, and good selectivity over a wide variety of other ions and redox species. The process for synthesizing the microparticles and fabricating the Pb(II)-sensor can be facilely scaled-up for use in the straightforward long-term online monitoring of Pb(II) ions in heavily polluted wastewaters. This study develops an understanding of the facile synthesis of conducting microparticles bearing many functional groups and their structures governing the potentiometric susceptibility toward interaction between Pb(II) ions and the microparticles for fabricating robust long-lived Pb(II)-sensor, signifying the potential suitability of such novel materials for inexpensive sensitive detection of Pb(II) ions.

Combinatorial screening of potentiometric Pb(II) sensors from polysulfoaminoanthraquinone solid ionophore.

A potentiometric Pb(II)-selective sensor was fabricated by a combinatorial screening of electrically conducting polysulfoaminoanthraquinone (PSA) nanoparticles as a solid ionophore, ion exchangers (oleic acid (OA) and NaTPB), plasticizers in a polyvinyl chloride (PVC) matrix, membrane thickness, inner filling ion species, and concentration. The membrane sensor with the composition of PSA/PVC/DOP (dioctyl phthalate)/OA (1.0:33:61:5.0) exhibited the best performance, including a slope of 29.3 mV decade(-1) in the concentration range 10(-6.3)-10(-1.6) M, detection limit of 1.6 × 10(-7) M, response time of 16 s, lifetime of five months, and good response reversibility. The proposed sensor has demonstrated good selectivity for Pb(II) over other monovalent, divalent and trivalent interfering ions, and could be used in a pH range of 3.62-5.22. The Pb(II) sensor has been successfully applied for the determination of Pb(II) concentration in real-world samples and also as an indicator electrode for potentiometric titration of lead ions.

Lead-ion potentiometric sensor based on electrically conducting microparticles of sulfonic phenylenediamine copolymer.

A potentiometric sensor to detect lead ions using newly synthesized conducting copolymer microparticles as an ionophore in self-supporting poly(vinyl chloride) membrane matrix plasticized with dioctyl phthalate was developed. The copolymer microparticles containing many ligating functional groups including amino, imino and sulfonic groups were synthesized by a chemical oxidative copolymerization of m-phenylenediamine (mPD) and p-sulfonic-m-phenylenediamine (SPD) in pure water. Due to the presence of -NH-, -N=, -NH2, and -SO3H ligating groups on the microparticles, a linear Nernstian response is obtained within a Pb(II) activity range from 1.00 × 10(-6) M to 1.00 × 10(-3) M. The Pb(II)-sensor containing the mPD/SPD (95/5) copolymer microparticles with the maximal electrical conductivity demonstrates a superior detection limit down to 1.26 × 10(-7) M, short response time to 14 s, and long lifetime of up to 4 months. The Pb(II)-sensor also exhibits a selective response to Pb(II) over 9 other metal ions and a pH independent plateau between 2.7 and 5.0. These advantages could make for a robust sensor performing credible analysis of Pb(II) concentration in real-world samples at trace levels.

Lead ion-selective electrodes based on polyphenylenediamine as unique solid ionophores.

A novel membrane electrode for Pb(II) ion detection based on semi-conducting poly(m-phenylenediamine) microparticles as a unique solid ionophore was fabricated. The electrode exhibited significantly enhanced response towards Pb(II) over the concentration range from 3.16×10(-6) to 0.0316 M at pH 3.0-5.0 with a low detection limit of 6.31×10(-7) M, a high sensitivity displaying a near-Nernstian slope of 29.8 mV decade(-1) for Pb(II). The electrode showed a long lifetime of 5 months and a short response time of 14s. A systematical investigation on the effect of anion excluder and various foreign ions on the selectivity of the electrode by a fixed interference method suggests that all other metal ions hardly ever interfere with the determination of Pb(II) except high concentration Hg(II). The electrode was successfully used as an indicator electrode in the potentiometric titration of Pb(II) with EDTA. Furthermore, the electrode has been used to satisfactorily analyze four types of real-world samples like spiked human urine, spiked tap water, and river water containing interfering ions like Na(I), Ca(II), Mg(II), Zn(II), Pd(II), Fe(III), K(I), Cu(II) and Hg(II) up to 8.04×10(-4) M, demonstrating fast response, high selectivity, good recovery (96.6-121.4%), good repeatability (RSD 0.31-6.45%), and small relative error (5.0%).