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PubMed1996

Fibrin glue application in conjunction with tetracycline root conditioning and coronally positioned flap procedure in the treatment of human gingival recession defects.

A split-mouth clinical study was designed to determine the effect of fibrin glue (FG) in addition to tetracycline HCI (TTC) root conditioning and the coronally positioned flap (CPF) procedure in the treatment of maxillary buccal recession defects. 11 patients presenting with a pair of Class I or II recession defects were selected. After initial therapy, defect-specific and full-mouth oral hygiene standards and gingival condition, recession depth, recession width, probing depth, attachment level, and width of keratinized gingiva were recorded. The surgical procedure included elevation of a full split thickness flap, root debridement and root conditioning with a 10 mg/ml TTC solution for 4 minutes. According to a randomization list, in each patient, 1 defect was treated with topical FG application, while the paired defect did not receive FG. The flap was adapted and sutured coronally to the cemento-enamel junction without tension. Healing was evaluated 6 months postsurgery. Significant recession depth reduction and attachment gain were observed for both treatments. Average root coverage amounted to 65% in FG treated defects and 55% in defects treated with TTC conditioning only. There were no clinical and statistical significant differences between the treatments for any parameter considered. This study suggests that FG may not meaningfully enhance the outcome of the CPF procedure with TTC root conditioning.

Administration, Topical↗
PubMed2002

A preliminary study of the percentage of gutta-percha-filled area in the apical canal filled with vertically compacted warm gutta-percha.

AIM: The aim of this study was to determine the influence of the width of apical root canals and the depth of heat application during warm vertical compaction on the percentage of gutta-percha-filled area (PGFA) in the apical root canal. METHODOLOGY: Two groups of extracted human canines (total 60) were instrumented and filled with vertically compacted warm gutta-percha up to the apical foramen (AF). Using the Touch 'n Heat device heat was applied 4 mm from the AP in one group and 2 mm in the other. The number of teeth with gutta-percha extrusion was recorded. A horizontal section was cut 1.5 mm from the AF of each tooth. The cross-sectional area of the canal and the gutta-percha was measured using an image-analysis programme. The PGFA was then calculated. Multiple linear regression was performed to investigate the association between the experimental variables and the PGFA, and the occurrence of gutta-percha extrusion. RESULTS: A significant association was seen between the depth of heat application and the PGFA (P= 0.000), and between the canal area and the PGFA (P= 0.038). The average PGFA reached 96.1% when heated to 2 mm, as compared with 87.0% when heated to 4 mm. PGFAs were lower in wide apical canals than in small canals. Gutta-percha extruded in seven teeth (12%) and was independent of experimental variables. CONCLUSIONS: After warm vertical compaction, the quality of adaptation of gutta-percha to the wall of the apical root canal varies; the influencing factors in this study were the depth of heat application and the width of the apical root canal.

Cuspid↗
PubMed1980

Heine's principle in vergence stimulation.

When left and right pairs of vertical parallel lines are presented stereoscopically with some disparity, they fuse so that they are perceived as a single pair of lines separated in depth. Heine showed that when such line pairs are rotated about the lines of sight in the same direction and by equal amounts from the vertical, their perceived separation in depth increases, an effect which results from the increase on horizontal disparity. This report describes how certain aspects of Heine's principle can be adapted to manipulate vergence stimulation. The technique can be implemented with very simple equipment. Possible applications of this method in binocular vision management are suggested.

Accommodation, Ocular↗
PubMed2006

No adaptation in the amplitude modulation domain in trained listeners.

The present study shows that on average, exposure to a 15 min, 5 kHz tone modulated sinusoidally in amplitude at 16 Hz with a 100% depth does not affect significantly amplitude modulation (AM) detection thresholds measured between 4 and 64 Hz when listeners are extensively trained to the AM detection task, with and without adaptor before data collection. These results are compatible with previous work given that a clear 6-dB adaptation effect was observed during the first pilot trials. However, the results reveal that adaptation effects are not robust, and suggest that the mechanisms underlying adaptation to AM must be reevaluated.

Acoustic Stimulation↗
PubMed2004

[Analgesia and sedation in intensive care medicine].

Sedation and analgesia are relevant aspects for the adequate treatment of patients in an intensive care unit. Recent drug developments and new strategies for ventilation provide improved sedation management allowing better adaptation to the clinical background and individual needs of the patient. This article provides an overview on the application of different substance groups. Focus is placed on newly developed pharmaceuticals such as dexmedetomidine. Another aspect is scoring system-related and EEG-based monitoring of depth of sedation. Modern concepts of analgesia and sedation for ICU patients have been developed based on the interaction of different parameters such as adaptive sedation and analgesia management (ASAM).

Analgesia↗
PubMed2005

Adaptation to long-term prostate cancer survival: the perspective of elderly Asian/Pacific Islander wives.

Increasingly evident is the important role of partners in patients' adaptation to diagnosis, treatment, and recovery. Yet, little is known about partners' adaptation when patients reach the benchmark known as long-term survival. This study describes elderly wives of prostate cancer survivors' perspectives of adaptation to the enduring challenges of prostate cancer survival and considers their experience in the context of ethnicity. Content analysis and grounded theory methods guided data collection and analysis of two waves of in-depth interviews with 26 elderly Asian/Pacific Islanders (Chinese, Filipino, Japanese, Native Hawaiian) living in Hawai'i. Continuous learning was the most common phenomenon as reflected in four types of adaptive work: involvement in husband's health, affirmation of the marital bond, normalization of adversity, and participation in personally meaningful acts. Issues are highlighted for consideration in developing culturally relevant, age-appropriate, and strengths-based interventions.

Adaptation, Psychological↗
PubMed1999

Enhanced post crown retention in resin composite-reinforced, compromised, root-filled teeth: a case report.

The introduction of an intraradicular composite reinforcing technique, in conjunction with the reestablishment of matching post canal spaces, has allowed compromised, root-filled teeth to be restored with functional, esthetic post crowns. This clinical case report suggests that reconstituted post canals, in accurately adapting to passive, parallel-sided, matching, and well-fitting posts, can enhance the retention of post crowns. Other factors of clinical importance relating to the resin-reinforced technique are discussed, including fracture resistance, depth of polymerization, dentin adhesion, polymerization shrinkage, and coronal microleakage.

Adult↗
PubMed1999

[The use of remifentanil in critically ill patients. Clinical findings and early experience].

OBJECTIVES: It was the aim of this investigation to report our initial clinical experience on the use of remifentanil in critically ill patients undergoing mechanical ventilation. Additionally, we hypothesized that even under intensive care conditions remifentanil might facilitate a temporally predictable and "programmed" tracheal extubation. METHODS: Remifentanil was used for analgesia and sedation of mechanically ventilated patients who were admitted to the ICU following major noncardiac surgery or who had to be ventilated due to respiratory failure. The infusion was started with 0.15 microg/kg/min and then adapted in steps of 0.05 microg/kg/min according to clinical needs. After admission to the ICU the depth of sedation was adjusted to a Ramsay score level of 4 (sleeping patient, immediately arousable) and then targeted at a level of 2-3 (patient awake, co-operative and tranquil or responding to command only). In case of sufficient pain relief but inadequate sedation patients could receive bolus doses of midazolam (1-3 mg) or an infusion of clonidine (0.5 microg/kg/h), the latter especially in case of shivering or hypertension. Prior to extubation bolus doses of piritramide (3-5 mg) and a non-opioid analgesic (metamizol or propacetamol) could be used for postoperative pain relief. Data are presented as mean+/-SD. RESULTS: A total of 46 patients were studied, aged 62.8+/-15.4 yr with a mean APACHE II score of 19.2 points. The duration of remifentanil infusion ranged up to 78 h with a mean of 9. 8 h. The mean infusion rate was 0.14+/-0.08 microg/kg/min during ongoing analgesia and sedation and 0.10+/-0.08 microg/kg/min immediately before its discontinuance. Additional sedatives were necessary in 63% of all patients. Emergence was rapid in the majority of cases: 67% of all patients could safely be extubated within 15 min after termination of remifentanil, and a total of 87% were extubated within 45 min. A development of tolerance was not observed during the study period. CONCLUSIONS: Remifentanil appeared to be suitable for analgesia and sedation of critically ill patients undergoing mechanical ventilation: Even under intensive care conditions recovery was rapid in the majority of cases, and in two thirds of all patients tracheal extubation was temporally predictable and could be timed within 15 min. These results are best explained by the metabolism and offset of action of remifentanil obviously unaffected in the ICU area. However, for fast emergence the cautious use of additional sedatives is crucial.

APACHE↗
PubMed1989

Hyperacuity, superresolution and gap resolution in human stereopsis.

Different types of stereoscopic acuity were studied with tasks adapted from studies of visual direction acuity. Dynamic, random-element stereograms portraying multiple surfaces in depth and a temporal 2AFC procedure were used for all measurements. The three tasks required detection of a depth offset (Hyperacuity task), a depth-axis thickening (Superresolution task), and a depth-axis gap between surfaces (Gap Resolution task). Thresholds for the three tasks were on the order of 3 sec arc, 30 sec arc and 200 sec arc of retinal disparity, respectively. These results are comparable to those for the analogous visual direction tasks on which they were patterned, suggesting that the underlying judgments involved are similar. Results are used to estimate the intrinsic noise of horizontal disparity processing.

Depth Perception↗
PubMed2005

An action-research study exploring midwives' support needs and the affect of group clinical supervision.

OBJECTIVE: To explore community midwives' views and experiences of their support needs in clinical practice, and then to identify how they would wish to receive such support. Further objectives were to redress the imbalance identified by planning and facilitating a model of clinical supervision devised by the participating midwives. DESIGN: A qualitative study using an action-research approach based on collaboration and participation. Action research has the potential to facilitate understanding of, and is able to adapt to, changing situations within clinical practice. Data were collected in three phases using in-depth interviews and focus groups. SETTING: A large maternity unit in the north of England, UK. PARTICIPANTS: Eight National Health Service (NHS) community midwives working in the same team. FINDINGS: Recent and ongoing organisational change and increased demands placed on the midwives by their managers were found to be detrimental to the process of clinical supervision and working relationships with their peers and clients. These pressures also inhibited the process of change. The midwives' behaviour and coping strategies revealed an apparent lack of understanding on their part, and that of their midwifery managers, of the regulation of emotion and the amount of energy this generated. Pseudo-cohesion and resistance to change were key defence mechanisms used by the participating midwives. KEY CONCLUSIONS: A large amount of published literature supported the existence of stress and burnout in midwifery, but no research addressed ways of alleviating this situation. Effective facilitation of midwifery support is needed, which can be met through support mechanisms such as clinical supervision. During the process of clinical supervision, strong messages emerged about the necessity to ensure that midwives are prepared educationally for the difficult situations that are brought about through collaborative working. There are also messages about the cultural legacy of NHS midwifery and how this can inhibit autonomous behaviour by midwives. IMPLICATIONS FOR PRACTICE: Developing and increasing self-awareness is still not viewed as being intrinsic to the work of the midwife, and midwives are being asked to undertake a level of work for which they have not been adequately prepared. The bureaucratic pressures of working in a large maternity unit exaggerate this further. In this situation, the system is seen as more important than the midwives.

Burnout, Professional↗
PubMed2002

Biomass development in slow sand filters.

Microbial biomass development in the sand and schmutzdecke layer was determined in two full-scale slow sand filters, operated with and without a light excluding cover. A standard chloroform fumigation-extraction technique was adapted to routinely measure microbial biomass concentrations in the sand beds. Sand was sampled to a depth of 10 cm and schmutzdecke was also collected at the same random positions on the uncovered filter. Interstitial microbial biomass in the uncovered sand bed increased with time and decreased with sampling depth. There was a small accumulation of sand biomass with time in the covered filter, but no relationship was apparent between biomass concentration and depth in this filter. Schmutzdecke did not develop on the covered filter and was spatially highly variable in the uncovered condition compared to the consistent patterns observed in interstitial biomass production. It is speculated that microbial biomass in the sand of uncovered filters is largely related to carbon inputs from photosynthetic activity in the schmutzdecke and involves mechanisms that spatially distribute carbon substrate from the schmutzdecke to the sand. However, total organic carbon and dissolved organic carbon removals were similar in both filters suggesting that relatively small biomass populations in covered filters are sufficient to remove residual labile carbon during advanced water treatment and little further advantage to water purification and organic carbon removal is gained by the increased production of biomass in uncovered slow sand filter beds.

Biomass↗
PubMed2000

Three-dimensional modelling of mercury cycling in the Gulf of Trieste.

The Gulf of Trieste (Northern Adriatic) is subject to mercury pollution from a former mercury mine in Idrija, located along a river which transports mercury-contaminated sediments into the Gulf. Concentrations in suspended and bottom sediments are up to two orders of magnitude higher than in the central and southern Adriatic. Extensive research has been carried out on measurements and modelling of the transport and fate of mercury in the Gulf. Two- and three-dimensional models have been developed to include the influence of the significant advective transport due to currents. Wind, thermohaline forcing, and the Soca river momentum are the most important forcing factors. A two-dimensional model simulated the transport of non-methylated and methylated mercury in dissolved, particulate and plankton fractions. Mercury processes included the input of atmospheric mercury, sedimentation, reduction, methylation and demethylation. The model simulations gave basically what were proper trends of the phenomena; quantitatively the measured and computed results are mainly within a factor of three. To simulate the non-uniform distribution of parameters over the depth, an existing three-dimensional (3D) hydrodynamic and transport-dispersion (TD) model, PCFLOW3D, was adapted and applied. As it was found that most mercury transport is related to suspended sediment particles, a new 3D sediment transport module was also developed and included in the model. Three cases are presented: one describing the simulation of TD of dissolved total mercury; another the simulation of the TD of particulate mercury in the Gulf during a river flood; and the third simulating sediment transport in the Gulf during a period of strong ENE wind. Comparison with measurements was only partly possible, but mainly the computed and measured results were within a factor of two and proper trends of the phenomena were obtained by the simulations. The combination of modelling and measurements has resulted in some interesting conclusions about the phenomenon of the transport and fate of mercury in a coastal sea.

Animals↗
PubMed1994

[Duration of anesthesia and mode of administration of Diprivan].

The dosage regimen to maintain propofol anaesthesia should ensure adequate depth of anaesthesia for the procedure, and allow a swift recovery. If the dosage is not adapted to the various phases of surgery, there is a risk of awareness especially after painful stimuli. This awareness is not always announced by signs which would allow its prevention. It is characterized by patient's movements but does not result in a memorization of the episode, except if the patient opens his eyes at that moment. Conversely, if propofol blood concentration is maintained at a sufficiently high level to prevent such unexpected movements, it will be necessary to reduce this concentration in the last stage of surgery to avoid a delayed recovery. Intermittent bolus injections and not controlled infusions are gradually abandoned. The optimal use of propofol should rely on the: 1. Use of an infusion pump (volumetric pump) which ensures regular administration: 2. Correct choice of administration technique, that ensures the most stable anaesthesia regardless of the type of operation, using the least possible amount of anaesthetic agent; 3. Combination of points 1 and 2, the first intellectual step towards progressively acquainting anaesthetists with the simultaneous use of an automated administration associated with a computer, which is the most reliable and effective technique today.

Anesthesia, Intravenous↗
PubMed1999

The role of the gut in major surgical postoperative morbidity.

Gut mucosal hypoperfusion has been termed the motor of multiple organ failure. While a large proportion of high-risk surgery proceeds unremarkably, the insult to the inflammatory system during perioperative periods of regional hypoperfusion may manifest themselves over the subsequent few days, leading to microvascular thrombi, organ dysfunction, and failure. Several approaches have been made to prevent this, including systemic optimization of the cardiovascular system and specific targeting of the splanchnic circulation with monitoring techniques such as tonometry or metabolic markers of hepatic function to guide fluid and drug therapies. It is believed that in a proportion of patients such methods are not likely to suffice and gut mucosal hypoperfusion is probable. If these patients can be identified preoperatively, then recently developed techniques used prophylactically such as immunonutrition, passive and active immunization, specific antimediator agents, or nonspecific anti-inflammatory agents may help minimize the number of patients progressing to multiple organ dysfunction and failure. Techniques that may help us identify at-risk patients may include in-depth cardiovascular assessment, possibly with echocardiography or a noninvasive cardiac output monitor such as the suprasternal adaptation of the ODM esophageal Doppler. The measurement of baseline endotoxin immune status (EndoCAb) may select those patients in advance who are most at-risk from gut mucosal hypoperfusion, thus allowing a more rational use of tonometry. Conventional risk scoring systems used in conjunction with knowledge of the type of surgery to be undertaken and whether large fluid shifts are likely along with the less conventional techniques discussed above may enable perioperative therapy to be closer to optimal.

Cardiac Surgical Procedures↗
PubMed2002

Does ileal reverse segment in rats with short bowel syndrome change intestinal morphology?

BACKGROUND: The primary goal of surgical therapy for short bowel syndrome is to increase intestinal absorptive capacity. Many surgical procedures have been described for this purpose. One of these is ileal reverse-segment procedure. This procedure after massive small-bowel resection is an alternative way to treat short bowel syndrome, but how it affects intestinal morphology in short bowel syndrome has not been investigated. The aim of this study is to investigate macroscopic and microscopic effects of reverse-segment procedure on the short bowel. METHODS: Twenty rats underwent resection of 80% of the small bowel. The rats were separated into two groups (n = 10). In the first group (reverse group), a reverse segment was formed by twisting a 2-cm ileal segment 180 degrees, without damaging its vascularity. In the second group (control group), a 2-cm ileal segment was resected, preserving its mesentery, and end-to-end anastomosis was performed to maintain the intestinal passage. The segment was not twisted 180 degrees. The 2-cm proximal (jejunal) and distal (ileal) segments of the resected bowel were reserved for histologic investigation. Two months later, the rats were killed and the jejunal and ileal segments were evaluated morphologically. RESULTS: In the reverse group, body weight and total intestinal length significantly increased (14% more than in the control group). The diameter of both proximal (jejunal) and distal (ileal) segments in the reverse group also increased 53.8% and 22.8%, respectively ( P < 0.05). Histologically, crypt depth and villus height of the ileal segment in the reverse group increased 15.2% and 18.2% more than in the control group ( P < 0.05). No histologic change was observed at the jejunal level except for intestinal muscle thickness. CONCLUSIONS: Ileal reverse-segment procedure in rats with short bowel syndrome 1) does not cause intestinal obstruction, 2) increases total bowel length and body weight, 3) increases the diameter of both jejunal and ileal segments, and 4) increases villus height and crypt depth only at the ileal level. For this reason, reverse-segment procedure positively affects intestinal adaptation.

Adaptation, Physiological↗
PubMed2005

Spike timing dependent plasticity (STDP) can ameliorate process variations in neuromorphic VLSI.

A transient-detecting very large scale integration (VLSI) pixel is described, suitable for use in a visual-processing, depth-recovery algorithm based upon spike timing. A small array of pixels is coupled to an adaptive system, based upon spike timing dependent plasticity (STDP), that aims to reduce the effect of VLSI process variations on the algorithm's performance. Results from 0.35 microm CMOS temporal differentiating pixels and STDP circuits show that the system is capable of adapting to substantially reduce the effects of process variations without interrupting the algorithm's natural processes. The concept is generic to all spike timing driven processing algorithms in a VLSI.

Action Potentials↗
PubMed2004

A digital ultrasonic system for small animal imaging.

In this paper, a 50 MHz digital ultrasonic imaging system designed for small animals and its applications to mouse embryos and tumors are presented. Utilizing the programmability of a fully digital system, several advanced imaging techniques are developed and implemented. A synthetic aperture focusing technique is implemented to increase the penetration and extend the depth of focus of a mechanical scan system using a high frequency single crystal transducer. An adaptive weighting technique is introduced to further reduce the sidelobes and enhance image contrast. Experimental results demonstrate efficacy of the proposed two-step adaptive focusing technique. For flow imaging, several flow estimation algorithms are evaluated. Simulations and flow phantom experiments show that the butterfly search technique offers superior flow imaging performance particularly when the SNR is low and the pulse bandwidth is high. The system is tested by imaging mouse embryos and microcirculation of a mouse tumor in vivo. It is demonstrated that the system is capable of simultaneously acquiring B-mode, color Doppler mode and power Doppler mode small animal images. The system set-up, adaptive focusing technique, flow estimation algorithms and imaging results are shown.

Algorithms↗