A molecular nanocap activated by superparamagnetic heating for externally stimulated cargo release.

A novel thermoresponsive snaptop for stimulated cargo release from superparamagnetic iron oxide core - mesoporous silica shell nanoparticles based on a [2 + 4] cycloreversion reaction (retro-Diels Alder reaction) is presented. The non-invasive external actuation through alternating magnetic fields makes this material a promising candidate for future applications in externally triggered drug delivery.

Magnetic field activated drug delivery using thermodegradable azo-functionalised PEG-coated core-shell mesoporous silica nanoparticles.

Core-shell Fe3O4@SiO2 mesoporous silica nanoparticles coated with a new thermodegradable polymer allowed the release of a model drug through heating caused by a high frequency oscillating magnetic field. The thermodegradable polymer was made of poly(ethylene glycol) (PEG) functionalised with azo bonds that break with an elevation of temperature.

Nanovalve activation by surface-attached photoacids.

Proton transfer caused by excitation of a photoacid attached to the surface of a mesoporous silica nanoparticle activates a nanovalve and causes release of trapped molecules. The protonation of an aniline-based stalk releases a noncovalently bound cyclodextrin molecule that blocked a pore. The results show that pH-responsive molecular delivery systems can be externally controlled using light.

Analysis of long-term outcomes for combined pars plana vitrectomy (PPV) and glaucoma tube shunt surgery in eyes with advanced glaucoma.

PURPOSE: To analyze 12- and 24-month visual acuity, intraocular pressure, and complications associated with combined pars plana vitrectomy (PPV) and glaucoma tube shunt placement in eyes with glaucoma. PATIENTS AND METHODS: A retrospective chart review was performed of patients with advanced glaucoma who underwent combined PPV and tube shunt surgery from 2006 to 2010. A minimum of 12 months of follow-up was required for their inclusion in the study. Visual acuity, intraocular pressure, complications, and number of glaucoma medications at 1 and 2 years postoperatively were analyzed. RESULTS: Twenty-eight eyes met the inclusion and exclusion criteria. Baseline visual acuity was 20/200 or worse in 14/28 eyes (50.0%) and 20/40 or better in 2/28 eyes (7.1%). Visual acuity remained 20/200 or worse in 50.0% (P=0.921) and 44.4% (P=0.973) of eyes after 1 and 2 years postoperatively, respectively. At baseline, the mean intraocular pressure was 30.4 mm Hg. There was significant improvement in mean IOP at 1 year (14.7 mm Hg, P=0.001) and at 2 years (15.2 mm Hg, P=0.001) postoperatively. Baseline number of glaucoma medications averaged 3.0±1.09 (SD), and improved to 1.8±1.28 (SD) at 1 year (P=0.0002) and to 1.4±1.33 at 2 years (P<0.0001) postoperatively. CONCLUSION: In this retrospective interventional case series, surgical management of advanced glaucoma with a combination of PPV and glaucoma tube shunt resulted in significantly reduced IOP and glaucoma medications at 1 and 2 years postoperatively.

Association between lower optic nerve laser Doppler blood volume measurements and glaucomatous visual field progression.

AIM: To perform a preliminary assessment of the relation between optic nerve circulatory parameters and glaucomatous visual field progression. METHODS: This study included 29 eyes of 23 patients with open angle glaucoma that had typical glaucomatous nerve fibre bundle visual field defects and increased cup to disc ratios. Laser Doppler flowmetry (Oculix) was used to measure relative optic nerve blood volume (Vol), velocity (Vel) and flow in the superior temporal (ST) and inferior temporal (IT) neuroretinal rim of the optic nerve. After blood flow measurements patients were followed for 6-62 months (mean 33 (SD 17) months) and 2-11 Humphrey visual fields (4.7 (2.6) fields) were obtained. Progression of glaucoma was assessed by the slope of the corrected pattern standard deviation (CPSD) values versus time, which was calculated manually for each eye using regression analysis. RESULTS: A significant negative correlation was observed between Vol in the IT rim and the CPSD slope (r=-0.56, p=0.002); patients with lower Vol tended to show faster progression of glaucomatous field damage than those with higher Vol. When the eyes were arbitrarily divided into two groups according to lower Vol (0.32 (0.06) arbitrary units, AU, n=15) or higher Vol (0.49 (0.06) AU, n=14), those with lower Vol had significantly worse mean CPSD slopes (0.50 (0.48) dB/year) than those with higher Vol (-0.67 (1.38) dB/year; Student's t test, p=0.009). CONCLUSIONS: In the IT rim, the area most prone to develop glaucomatous field damage, lower Vol is associated with subsequently faster CPSD progression. These measurements suggest that circulatory abnormalities may have a role in the development of glaucoma.

Synthesis and luminescence spectroscopy of a series of [eta(5)-CpFe(CO)2] complexes containing 1,12-dicarba-closo-dodecaboranyl and -ylene ligands.

Three new cyclopentadienyliron dicarbonyl compounds, 1-[eta(5)-CpFe(CO)(2)]-1,12-C(2)B(10)H(11), 1-[[eta(5)-CpFe(CO)(2)]-1,12-C(2)B(10)H(10)-12-yl](2)Hg, and 1,12-[eta(5)-CpFe(CO)(2)](2)-1,12-C(2)B(10)H(10), composed of 1,12-dicarba-closo-dodecaborane as a ligand precursor were synthesized and found to be luminescent. The uncoordinated 1,12-C(2)B(10)H(12) bridging ligand precursor is luminescent with a band maximum at 25180 cm(-1), while the iron complexes luminesce at lower energies in the range 13120-14210 cm(-1). The lowest energy excited electronic state in the iron complexes is assigned to a ligand field transition of the iron chromophore. Cyclic voltammetry of 1,12-[eta(5)-CpFe(CO)(2)](2)-1,12-C(2)B(10)H(10) displays two discrete one-electron oxidations, and the luminescence maximum is red shifted from that observed in 1-[eta(5)-CpFe(CO)(2)]-1,12-C(2)B(10)H(11). Both of these observations suggest that the iron-centered chromophores are weakly coupled. In contrast, the 1-[[eta(5)-CpFe(CO)(2)]-1,12-C(2)B(10)H(10)-12-yl](2)Hg complex is uncoupled as is evident from the single oxidation process observed with cyclic voltammetry. The extinction coefficient of 1,12-[eta(5)-CpFe(CO)(2)](2)-1,12-C(2)B(10)H(10) is six times that of 1-[eta(5)-CpFe(CO)(2)]-1,12-C(2)B(10)H(11), while the extinction coefficient of 1-[[eta(5)-CpFe(CO)(2)]-1,12-C(2)B(10)H(10)-12-yl](2)Hg is only twice that of 1-[eta(5)-CpFe(CO)(2)]-1,12-C(2)B(10)H(11). These spectroscopic properties are explained in terms of two coupled antiparallel transition dipole moments.

["Deficiencies in the mandatory health insurance system"--possibilities and limits of medical expert assessment]. / "Mangel des gesetzlichen Leistungssystems"--Möglichkeiten und Grenzen der medizinischen Sachverständigentätigkeit.

In Germany, the Federal Committee of Physicians and Health Insurance Agencies is responsible for assessing which medical procedures are covered by the insurance agencies (therapeutic/economic value). The failure to evaluate certain medical procedures which promise therapeutic benefit may be considered a failure in the system of statutory health insurance as decreed by the German Federal Social Court. In cases of system failure the assessment of medical procedures is taken over by social courts. Evidence of therapeutic value will continue to be the decisive criterion of evaluation. In special cases, however, it may be replaced by the particular procedure's rate of incidence in everyday medical practice, as reflected by a widespread resonance in medical discussion and its use by a considerable number of physicians. Medical experts may face various difficulties in handling these alternative criteria. They usually lack reliable data on the frequency of the procedure, i.e. its distribution. Even if such data and data on secondary factors--such as disease incidence etc.--were available to them, they would still not be able to come up with a definite conclusion on the degree (widespread, considerable) of dissemination, as defined by the German Federal Social Court. Nevertheless, on request of statutory health insurances, social medical experts may investigate facts in order to establish basic knowledge for later decisions that are to be done by others. Factual investigation includes clarification of etiology, incidence, importance and natural history of the particular disease processes. Potential deficiencies in the medical services rendered for specific diseases as well as the characteristics of the procedure under scrutiny, and special requirements for evaluating the outcome have to be investigated as well. Additional attention needs to be paid to the quality of related publications (analysis of statistical data), possible recommendations for therapy (e.g. guidelines and their scientific basis), as well as to economic aspects. The result of such an investigation has to be stated without use of court criteria (widespread/considerable).

Clinical integration and nursing leadership across an integrated delivery system.

As new health systems struggle to combine in today's challenging health care market, mechanisms that facilitate and enhance integration become increasingly important. This article describes the use of clinical paths in an integrated delivery system (IDS) as a methodology to establish a single standard of high-quality care. Through education and sharing of staff development resources across the IDS, the system nurse executive at one large IDS promotes professional practice. As clinical paths are developed across the system, the best clinical practice is put to paper, providing a framework for outcome-driven care. The nurse manager assesses staff's use of clinical paths as an evaluation of their skills and competency and to identify new educational and growth opportunities.

[Quality control in ambulatory health care. Results of an area-wide study by the public medical service of the Baden-Württemberg health insurance]. / Qualitätsprüfung ambulanter Pflegedienste. Ergebnisse einer flächendeckenden Untersuchung durch den Medizinischen Dienst der Krankenversicherung Baden-Württemberg.

Discussions surrounding the quality of nursing care, fueled by recurring press reports, prompted the State Nursing Insurance Associations in Baden-Wuerttemberg to request the Health Insurance Medical Service to perform a quality control of outpatient nursing care services in the state. Based on a coordinated concept and for the first time in the Federal Republic of Germany, all authorized ambulatory institutions area-wide were subjected to a uniform assessment (total survey) during an official inquiry time period. The end results of these controls failed to verify the judgement often propagated by the press based on individual cases that high-quality nursing care can no longer be afforded under the present circumstances. On the average, 55% of the personnel provided to patients by outpatient nursing services were health care professionals. What is more, this professional staff rendered 75% of all nursing care services. The evaluation of the accompanied medical visits indicated that the vast majority attempted to take active nursing care into account. With regard to quality assurance, a great optimisation potential was indicated primarily in the area of nursing documentation. Only in about 35% of the nursing documents inspected was the nursing procedure always clearly evident. A future problem could arise from the fact that of all nursing professionals with leadership responsibilities, at the time of the survey only about 37% had completed the requisite professional training qualification programme of 460 training hours. If the time before the interim deadline (March 31, 2002) is not utilised, the institutions in question could face consequences that could threaten their very existence. It is evident that a large number of outpatient nursing care services in the state of Baden-Wuerttemberg do not have their economic foundation in the domain of the Nursing Care Insurance Law, which affects both patient structure and care intensity. As a consequence, there is no quality control or inspection whatsoever for the majority of nursing care services rendered by ambulatory nursing care services at present because they are not under the jurisdiction of the German Federal Social Legislation SGB XI.

Analytical derivation of interference dips in molecular absorption spectra: molecular properties and relationships to Fano's antiresonance.

An analytical expression is derived for the decrease in the absorption cross section that occurs when two molecular electronic states are coupled by spin-orbit coupling. The loss of intensity, or interference dip, is common in the spectra of metal compounds. The derivation is based on a coupling of a single forbidden donor state to a broadened harmonic acceptor potential, and leads to simple analytical expressions. The new expressions give line shape functions different from those in the commonly used Fano antiresonance interpretation and are based on interpretable molecular properties.

Ligand to ligand charge transfer in (hydrotris(pyrazolyl)borato)(triphenylarsine)copper(I).

Emission and UV-vis absorption spectra of (hydrotris(pyrazolyl)borato)(triphenylarsine)copper(I), (CuTpAsPh3), (hydrotris(pyrazolyl)borato)(triethylamine)copper(I), (CuTpNEt3), and (hydrotris(pyrazolyl)borato)(triphenylphosphine)copper(I), (CuTpPPh3), are reported. The spectra of the arsine complex contain low-energy bands (with a band maximum at 16,500 cm(-1) in emission and a weak shoulder centered at about 25,000 cm(-1) in absorption) that are not present in the corresponding spectra of the amine or phosphine complexes. The lowest energy electronic transition is assigned to ligand to ligand charge transfer (LLCT) with some contribution from the metal. This assignment is consistent with PM3(tm) molecular orbital calculations that show the HOMO to consist primarily of pi orbitals on the Tp ligand (with some metal orbital character) and the LUMO to be primarily antibonding orbitals on the AsPh3 ligand (also with some metal orbital character). The absorption shoulder shows a strong negative solvatochromism, indicative of a reversal or rotation of electric dipole upon excitation, and consistent with a LLCT. The trends in the energies of the electronic transitions and the role of the metal on the LLCT are discussed.

In-situ gas-phase luminescence and time-of-flight mass spectroscopic detection of photofragments during photochemical synthesis of copper particles from bis(tert-butylacetoacetato)copper.

During the 308 nm laser-driven photochemical synthesis of Cu particles from bis(tert-butylacetoacetato)copper, gas-phase photogenerated intermediates are identified by luminescence and time-of-flight mass spectroscopies. Pure Cu deposits are obtained as homogeneous, granular 200 nm particles. In the gas phase, luminescent photoproducts are observed and atomic Cu, Cu2, and dissociated ligand are identified spectroscopically. In addition, mass spectroscopy identifies Cu atoms, the dissociated ligand, a monoligated complex, and fragments of the ligands. The implications of the photofragmentation that produces copper atoms and dimers for the laser-assisted production of the Cu deposits are discussed.

Ischemic preconditioning improves the survival of skin and myocutaneous flaps in a rat model.

Inadequate blood supply of pedicle flaps results in partial necrosis, and prolonged ischemia during free-tissue transfer can result in partial or complete flap necrosis. Recent research in the field of cardiovascular surgery has shown that ischemic preconditioning (repeated brief episodes of coronary artery occlusion followed by reperfusion) improves myocardial muscle survival when the heart is subsequently subjected to prolonged ischemia. Preconditioning of skin or myocutaneous flaps as either pedicle or free flap models has never been studied. The goal of this investigation was to measure the effect of ischemic preconditioning on myocutaneous and skin flap survival areas and total necrosis rates after variable periods of global ischemia. In 220 rats, 100 transverse rectus abdominis myocutaneous flaps and 120 dorsal cutaneous flaps were randomized into treatment and control groups. The treatment flaps underwent preconditioning by three cycles of 10 minutes of pedicle clamping followed by 10 minutes of reperfusion for a total preconditioning period of 1 hour. The control flaps were perfused without clamping for 1 hour. Both control and treatment flaps then underwent global ischemia for 0, 2, 4, 6, 10, or 14 hours by pedicle clamping. Flap survival area was measured on the fifth postoperative day. Statistical analysis was performed with analysis of variance, student's t tests, and probit analysis. Preconditioning improved survival areas of pedicle myocutaneous flaps (0-hour group) from 47 +/- 16 percent (mean percent area surviving +/- SD) to 63 +/- 5 percent. This difference was statistically significant (t test, p < 0.04). There was no statistically significant improvement in pedicle skin flap survival. For free flap models (flaps undergoing global ischemia), preconditioning increased the survival areas of skin and myocutaneous flaps (analysis of variance, p < 10(-5)). For the skin flap model, statistical significance of the survival area difference was reached at 6, 10, and 14 hours of ischemia (t test, p < 10(-4)). The magnitude of this effect was higher in the myocutaneous flap model and reached statistical significance at 2, 4, 6, and 10 hours of ischemia (p < 10(-3)). Preconditioned flap survival areas were increased by two to five times that of non-preconditioned flaps at these ischemia times. Preconditioning lowered total necrosis rates at all ischemia times for both flap models. The critical ischemia time when 50 percent of skin flaps became totally necrotic (CIT50) improved from 6.9 to 12.4 hours by preconditioning. Similarly, preconditioning improved the CIT50 of myocutaneous flaps from 3.6 to 9.2 hours. For the first time, statistically significant improvements of partial necrosis areas and total necrosis rates have been demonstrated through intraoperative ischemic preconditioning of skin and myocutaneous flaps. In clinical practice, application of this technique may lead to improved survival during pedicled or free transfer of myocutaneous flaps and free transfer of skin flaps.

TRAM flap perforator ligation and the delay phenomenon: development of an endoscopic/laparoscopic delay procedure.

Despite its versatility in breast reconstruction, the TRAM flap is at times subject to ischemic compromise, especially in certain high risk populations. A preoperative delay procedure can decrease the likelihood of TRAM flap failure or fat necrosis, but the required extent of this delay procedure is not clearly defined. In an attempt to augment flap vascularity while reducing surgical dissection and morbidity, six distinct delay procedures and a nondelayed control were compared in a rat TRAM flap model (n = 8 for all groups). An important feature that was incorporated into several groups was the ligation of the contralateral rectus perforators through minimal skin incisions (endoscopic analogy, groups 4 to 7). The most effective delay procedure was the combination of contralateral rectus perforator ligation and ipsilateral dominant pedicle ligation (group 7), which was achieved with two minimal skin incisions and no significant flap undermining. This procedure reduced the flap necrosis from 63.2 +/- 5.8 percent (control) to 13.5 +/- 3.3 percent (p < 0.001). After completion of the animal studies, clinical application of a "minimally invasive" TRAM flap delay procedure was then undertaken in eight high risk patients with only modest ischemic compromise. Although the clinical experience is too early to draw definite conclusions, we feel that "endoscopic delay" has potential as a modality that will increase flap vascularity but minimize the morbidity of the preliminary procedure.

Comparison of the effects of ischemic preconditioning and surgical delay on pedicled musculocutaneous flap survival in a rat model.

Both surgical delay (SD) and ischemic preconditioning (IP) have been shown to be effective in improving the survival of pedicled musculocutaneous flaps. The goal of our study was to determine the effects of IP and SD, separately and together, on the survival of pedicled transverse rectus abdominis musculocutaneous (TRAM) flaps in a rat model. Thirty-two male Sprague-Dawley rats were divided into four groups of 8 rats each: (1) control, (2) 2-week SD, (3) IP, and (4) SD plus IP. A TRAM flap was elevated in each rat. Flap viability was assessed on the fifth postoperative day by computerized video planimetry. Mean area of flap survival was compared between the control, IP, SD, and SD plus IP groups using analysis of variance and Student's t-test. Improvement in surface area survival was seen in musculocutaneous flaps subjected to IP, SD, and SD plus IP compared with the control. IP and SD improved survival 1.3 and 1.4 times the control area respectively. Differences between treatment and control flaps were statistically significant (p < 0.04). In addition, the combination of SD plus IP improved survival by 1.8 times, which is statistically different from controls and from either technique individually (p < 0.002). IP and SD have similar efficacy in improving survival in this musculocutaneous flap model. The effects of IP and SD appear to be additive. The advantage of IP over SD is that IP can be performed during the same operative session as the flap elevation and only adds 1 hour to the surgical procedure.