Facile synthesis of MoO2/CaSO4 composites as highly efficient adsorbents for congo red and rhodamine B.

A novel rod-shaped MoO2/CaSO4 composite was prepared by using hexa-ammonium molybdate and flue gas desulfurization gypsum via a simple mixed-solvothermal route. In this composite, CaSO4 matrices are decorated with MoO2 nanoparticles, and non-structural mesopores are formed via particle packing. Moreover, it displays an excellent adsorption capability towards anionic congo red (CR) and cationic rhodamine B (RhB). The adsorption quantities per unit mass and removal efficiencies of the two dyes are significantly influenced by adsorbent dose, solution pH, and temperature. The adsorption isotherm data can be best fitted by the Langmuir model, and the calculated maximum adsorption quantities at 303.5 K are 853.54 mg g-1 for CR and 86.38 mg g-1 for RhB, respectively, which are superior to other common adsorbents. The corresponding kinetic data can be well matched with the pseudo-second-order model. Additionally, the CR adsorption is an exothermic process, while the RhB adsorption is an endothermic process. Both of them are multi-step chemisorption processes influenced by surface adsorption and intra-particle diffusion. This MoO2/CaSO4 composite can be applied as an alternative adsorbent for removing organic dyestuffs from printing and dyeing wastewater.

Self-assembled metallogels formed from N,N',N''-tris(4-pyridyl)trimesic amide in aqueous solution induced by Fe(III)/Fe(II) ions.

In this work, we report self-assembled metallogels formed from a ligand of trimesic amide, N,N',N''-tris(4-pyridyl)trimesic amide (TPTA), induced by Fe(III)/Fe(II) ions. TPTA is difficult to dissolve in water even in the presence of some metal ions such as Cu(2+), Co(2+), Ni(2+), K(+), Na(+) and Mg(2+) under heating, and it exhibits no gelation ability. Interestingly, upon heating TPTA can be dissolved easily in aqueous solution containing Fe(3+)/Fe(2+), and subsequently self-assembled into metallogels after cooling. The metallogels could also be formed in aqueous solutions of mixed metal ions containing Fe(3+)/Fe(2+), indicating that the other metal ions do not affect the formation of Fe(III)-TPTA and Fe(II)-TPTA metallogels. The high selectivity of metallogel formation to Fe(3+)/Fe(2+) may be used for application in the test of Fe(3+)/Fe(2+). The metallogels obtained are characterized by scanning electron microscopy, Fourier transform infrared spectra, nuclear magnetic resonance spectra, rheological measurements and scanning tunneling microscopy. The results indicate that TPTA can self-assemble into fibrous aggregates in Fe(3+)/Fe(2+) aqueous solution through the metal-ligand interactions and intermolecular hydrogen bonding. This kind of metallogel also possesses good mechanical properties and thermoreversibility.

A microporous hydrogen-bonded organic framework: exceptional stability and highly selective adsorption of gas and liquid.

An extremely stable hydrogen-bonded organic framework, HOF-8, was fabricated. HOF-8 is not only thermally stable but also stable in water and common organic solvents. More interestingly, desolvated HOF-8 exhibits high CO2 adsorption as well as highly selective CO2 and C6H6 adsorption at ambient temperature.

[Laparoscopic abdominoperineal resection for low rectal cancer].

OBJECTIVE: To assess the advantage and disadvantage of laparoscopic abdomino-perineal resection and open abdominoperineal resection for low rectal cancer. METHODS: Patients with low rectal cancer, collected from July 2003 to April 2006, were randomly divided into laparoscopic abdominoperineal resection group (37 cases) and open abdominoperineal resection group (37 cases). Operation time, number of lymph node removed, intra-operative blood loss, time to pass flatus, time to ambulate, time to discharge, complications, early recurrence, and economical cost were compared between the 2 groups. RESULTS: All patients were performed successfully. For the first 10 patients, operation time of laparoscopic group was significantly longer than that of open group, but there was no significant difference between the 2 groups. Intra-operative blood loss of laparoscopic group was significantly less than that of open group, but it was reverse for the first 10 patients. There was no significant difference in time to pass flatus between the 2 groups. Time to ambulate in laparoscopic group was significantly earlier than that in open group. There was no significant difference in time to discharge between the 2 groups, but it was earlier for perineum closure in laparoscopic group. Relative complications of laparoscopic group, including pulmonary infection, abdominal wound infection or split, were significantly less than those of open group. There was no significant difference in number of lymph nodes removed, early recurrence between the 2 groups. Operation cost of laparoscopic group was significantly higher than that of open group, but there was no significant difference. CONCLUSION: Advantages of laparoscopic abdominoperineal resection were characterized for not only minimal invasion and good cosmetic outcome but also less blood loss, complications, and earlier postoperative recovery. The operation time, total costs and oncological clearance of laparoscopic abdominoperineal resection patients were comparable with those of open procedure patients.

[One stage thyroidectomy and bilateral neck dissection for well-differentiated thyroid carcinoma].

OBJECTIVE: To investigate the indications, safety and difficulties of one stage thyroidectomy and bilateral neck lymph node dissection for well-differentiated thyroid carcinoma. METHODS: A retrospective review was carried out in 36 well-differentiated thyroid carcinoma patients so treated from 1990 to 2004. Various incisions including H, L and modified Kocher types were selected according to the location of primary tumor and status of cervical lymph node metastasis. Either total thyroidectomy or sub-total thyroidectomy combined with bilateral neck lymph node dissection according to the principles of modified radical neck lymph node dissection: preserving the internal jugular vein, spinal accessory nerve and sternocleidomastoid muscles. RESULTS: There was no operative death in this group. Postoperative complications included: 2 wound bleeding, 3 recurrent laryngeal nerve resection due to tumor involvement, 1 recurrent laryngeal nerve injury, 2 unilateral internal branch of superior laryngeal nerve injury, 9 unilateral external branch of superior laryngeal nerve injury, 3 unilateral accessory nerve injury, 5 unilateral sympathetic nerve injury, 2 unilateral phrenic nerve injury, 6 chylus fistula, 13 temporary hypoparathyroidism, 2 permanent hypoparathyroidism. The dissected lymph nodes were found to be positive from 0 to 21 in each patient with a mean of 8.3. Of the 36 patients: 31 had bilateral positive lymph nodes; 3 unilateral positive; 2 bilateral negative lymph nodes. The follow up period ranged from 1 to 13 years, Three patients died of distant metastasis, 1 died of cerebral vascular accident. 7 patients lost in follow-up. Totally, 25 patients are still alive, 3 patients had local relapse and were surgically treated again. CONCLUSION: The procedure of one-stage thyroidectomy and bilateral neck lymph node dissection for well-differentiated thyroid carcinoma is safe, as it is mandatory that at least one unilateral internal jugular vein should be preserved; one unilateral recurrent laryngeal nerves and accessory nerves should not be injured. Well-differentiated thyroid carcinoma patients whose bilateral cervical lymph nodes are clinically suspected to be positive (obviously enlarged, hard, purplish grapelike lymph node) or are confirmed pathologically to be positive are indications for one-stage thyroidectomy and bilateral neck lymph node dissection. Total or sub-total thyroidectomy should be undertaken with emphasis that at least one parathyroid with blood supply should be preserved. It is of utmost importance that not only the cancer be completely resected but the function of the organs be preserved.