Biomechanical stability of a posterior-alone fixation technique after craniovertebral junction realignment.

OBJECTIVE: The aim of the current study was to investigate the biomechanical stability and fixation strength provided by a posterior approach reconstruction technique to realign the craniovertebral junction.¦METHODS: We tested seven human cadaver occipito-cervical spines (occiput-C4) by applying pure moments of ±1.5 Nm on a spine tester. Each specimen was tested in the following modes: 1) intact; 2) injured; 3) spacers alone at C1-C2 articulation (S); 4) spacers plus C1-C2 Posterior Instrumentation (S+PI); and 5) spacers plus C1-C2 posterior instrumentation plus midline wiring (S+PI+MLW). C1-C2 range of motion for each construct was obtained in flexion-extension, lateral bending, and axial rotation.¦RESULTS: In all the loading modes, S, S+PI, and S+PI+MLW constructs significantly reduced range of motion compared with the intact and injured condition (P < 0.05). There was no statistical difference between any of the three instrumentation constructs (P > 0.05).¦CONCLUSIONS: This study investigated the biomechanics of the posterior approach technique for realignment of the craniovertebral junction and also made comparisons with additional posterior fixations. The stand-alone spacers were stable in all three loading modes. Posterior instrumentation increased the stability as compared to stand-alone spacers. The third point of fixation, carried out by using midline wiring, increased the stability further. However, there was not much difference in the stability imparted with the midline wiring versus without. The present study highlights the biomechanics of this novel concept and reaffirms the view that distraction of the C1-C2 articular facets and direct articular joint atlantoaxial fixation would be an ideal method of management of basilar invagination.

Arthro-IRM directe en traction axiale: technique et intérêt [Technique and value of direct MR arthrography applying articular distraction]

Direct MR arthrography has a better diagnostic accuracy than MR imaging alone. However, contrast material is not always homogeneously distributed in the articular space. Lesions of cartilage surfaces or intra-articular soft tissues can thus be misdiagnosed. Concomitant application of axial traction during MR arthrography leads to articular distraction. This enables better distribution of contrast material in the joint and better delineation of intra-articular structures. Therefore, this technique improves detection of cartilage lesions. Moreover, the axial stress applied on articular structures may reveal lesions invisible on MR images without traction. Based on our clinical experience, we believe that this relatively unknown technique is promising and should be further developed.

Spiral CT aortography: an efficient technique for the diagnosis of traumatic aortic injury.

The objective of this study was to assess the efficiency of spiral CT (SCT) aortography for diagnosing acute aortic lesions in blunt thoracic trauma patients. Between October 1992 and June 1997, 487 SCT scans of the chest were performed on blunt thoracic trauma patients. To assess aortic injury, the following SCT criteria were considered: hemomediastinum, peri-aortic hematoma, irregular aspect of the aortic wall, aortic pseudodiverticulum, intimal flap and traumatic dissection. Aortic injury was diagnosed on 14 SCT examinations (2.9 %), five of the patients having had an additional digital aortography that confirmed the aortic trauma. Twelve subjects underwent surgical repair of the thoracic aorta, which in all but one case confirmed the aortic injury. Two patients died before surgery from severe brain lesions. The aortic blunt lesions were confirmed at autopsy. According to the follow-up of the other 473 patients, we are aware of no false-negative SCT examination. Our limited series shows a sensitivity of 100 % and specificity of 99.8 % of SCT aortography in the diagnosis of aortic injury. It is concluded that SCT aortagraphy is an accurate diagnostic method for the assessment of aortic injury in blunt thoracic trauma patients.

Removal of unusual, large high-velocity metallic maxillary sinus foreign bodies by a modified free bone flap technique.

Metallic foreign bodies are rarely found in the maxillary sinus, and usually they have a dental origin.Potential complications related to foreign bodies include recurrent sinusitis, rhinolith formation, cutaneous fistula,chemical poisoning, facial neuralgic pain and even malignancies.Two main surgical approaches are currently used for the removal of foreign bodies in the maxillary sinus: the bone flap and the endoscopic sinus techniques. We are reporting two unusual cases of large high-velocity foreign bodies removed by a modified maxillary lateral antrotomy,with free bone flap repositioning and fixation with a titanium miniplate.

Operative Treatment of Ovarian Cancer and Borderline Tumors in Different Hospital Categories in Finland

Surgery is the cornerstone of ovarian cancer treatment and maximal cytoreduction is important. In the early 1980’s primary surgical treatment of ovarian cancer was performed in over 80 hospitals in Finland. The significance of the operative volume of the hospital, of the training of the surgeons and of centralization of surgical treatment has been widely discussed. The aim of the present study was to evaluate the outcome of surgical treatment of ovarian cancer in different hospital categories retrospectively and prospectively, and to analyze if any differences are reflected in survival. The retrospective study included 3851 ovarian cancer patients operated between 1983 and 1994 in Finland. The data was analyzed according to hospital category (university, central, and other) and by quartiles of the hospital operative volume. The results showed that patients operated in the highest operative volume hospitals had the best relative survival. When stratifying the analysis by the period of diagnosis (1983-1988 and 1989-1994), the university hospitals improved their performance the most. The prospective part of the thesis was initiated in 1999 and included 307 patients with invasive ovarian cancer and 65 patients with an ovarian borderline tumor. The baseline and 5-year surveys used a questionnaire that was filled in by the operating surgeons. For analysis of the 5-year followup data, the hospitals were divided into three categories (<10, 10-20, or >20 patients operated in 1999). The effect of the surgical volume was analyzed also as a continuous variable (1-47 operations per year). In university hospitals, pelvic lymphadenectomy was performed in 88 %, and para-aortic lymphadenectomy in 73 %, of the patients with stage I disease. The corresponding figures ranged from 11 % to 21 % in the other hospitals. For stage III ovarian cancer patients operated by gynecological oncologists, the estimated odds ratio for no macroscopic residual tumor was 3.0 times higher (95 % CI 1.2-7.5) than for those operated by general gynecologists. In the university and other hospitals 82% of the patients received platinum-based chemotherapy. Platinum + taxane combination was given to 63 % of the patients in the university and in 49 % in the other hospitals (p = 0.0763). Only a minority of the patients with tumors of borderline malignancy were staged according to recommendations, most often multiple peritoneal biopsies and omentectomy were neglected. FIGO stage, patient age, and residual tumor were independent prognostic factors of cancer-specific 5-year survival. A higher hospital operative volume was also a significant prognostic factor for better cancer-specific survival (p = 0.036) and disease-free survival (p = 0.048). In conclusion, ovarian cancer patients operated in high-volume university hospitals were more often optimally debulked and had a significantly better cancer-specific survival than patients operated in other hospitals. These results favor centralization of primary surgical treatment of ovarian cancer.

Via-configurable transistor array: a regular design technique to improve ICs yield

Process variations are a major bottleneck for digital CMOS integrated circuits manufacturability and yield. That iswhy regular techniques with different degrees of regularity are emerging as possible solutions. Our proposal is a new regular layout design technique called Via-Configurable Transistors Array (VCTA) that pushes to the limit circuit layout regularity for devices and interconnects in order to maximize regularity benefits. VCTA is predicted to perform worse than the Standard Cell approach designs for a certain technology node but it will allow the use of a future technology on an earlier time. Ourobjective is to optimize VCTA for it to be comparable to the Standard Cell design in an older technology. Simulations for the first unoptimized version of our VCTA of delay and energy consumption for a Full Adder circuit in the 90 nm technology node are presented and also the extrapolation for Carry-RippleAdders from 4 bits to 64 bits.

Mulching as an alternative technique for weed management in mandarine orchard tree rows

Peer reviewed

Four-corner bone arthrodesis with dorsal rectangular plate: series and personal technique.

Controversy exists about the best method to achieve bone fusion in four-corner arthrodesis. Thirty-five patients who underwent this procedure by our technique were included in the study. Surgical indications were stage II-III SLAC wrist, stage II SNAC wrist and severe traumatic midcarpal joint injury. Mean follow-up was 4.6 years. Mean active flexion and extension were 34 degrees and 30 degrees respectively; grip strength recovery was 79%. Radiological consolidation was achieved in all cases. The mean DASH score was 23 and the postoperative pain improvement by visual analogue scale was statistically significant. Return to work was possible at 4 months for the average patient. Complications were a capitate fracture in one patient and the need for hardware removal in four cases. Four-corner bone wrist arthrodesis by dorsal rectangular plating achieves an acceptable preservation of range of motion with good pain relief, an excellent consolidation rate and minimal complications.

An Image Enhancement Technique using MTF of Human eye

Image filtering is a highly demanded approach of image enhancement in digital imaging systems design. It is widely used in television and camera design technologies to improve the quality of an output image to avoid various problems such as image blurring problem thatgains importance in design of displays of large sizes and design of digital cameras. This thesis proposes a new image filtering method basedon visual characteristics of human eye such as MTF. In contrast to the traditional filtering methods based on human visual characteristics this thesis takes into account the anisotropy of the human eye vision. The proposed method is based on laboratory measurements of the human eye MTF and takes into account degradation of the image by the latter. This method improves an image in the way it will be degraded by human eye MTF to give perception of the original image quality. This thesis gives a basic understanding of an image filtering approach and the concept of MTF and describes an algorithm to perform an image enhancement based on MTF of human eye. Performed experiments have shown quite good results according to human evaluation. Suggestions to improve the algorithm are also given for the future improvements.

Suunnitelma Ethernet-pohjaisen TCP/IP-verkon toteuttamiseksi prosessitietoliikenteen tarpeisiin Helsingin Energiassa

Prosessitietoliikenneverkko toimii mm. energian tuotannon, siirron ja jakelun käytönvalvontajärjestelmien tiedonsiirron alustana. Tietoliikenneverkkojen rooli osana yrityksen operatiivisia prosesseja kasvaa järjestelmäuusintojen myötä ja järjestelmien tehokas hyödyntäminen vaatii luotettavat sekä nopeat tietoverkot. Uusittavien järjestelmien tietoliikenneratkaisut perustuvat pääsääntöisesti Ethernetpohjaiseen TCP/IP-verkkotekniikkaan. Tällä hetkellä prosessijärjestelmien tiedonsiirtoyhteydet kenttälaitteiden ja valvomojärjestelmien välillä on pääsääntöisesti toteutettu PCM-siirtojärjestelmällä tai kiinteän yhteyden modeemeilla. Käytössä oleva PCM-tekniikka on elinkaarensa loppupuolella ja tiedonsiirtonopeudet sekä liityntärajapinnat eivät täytä nykyaikaisten prosessijärjestelmien tiedonsiirto¬vaatimuksia. Työssä käytiin läpikeskeisimmät Ethernet-tekniikkaan ja TCP/IP-protokollaperheeseen liittyvät standardit ja verkon aktiivilaitteet. Vaatimusmäärittelyissä selvitettiin Helsingin Energian eri liiketoimintayksiköiden tarpeita sekä energia-alan lainsäädännön vaatimuksia prosessitietoliikenneverkolle. Tarpeiden ja vaatimusten pohjalta verrattiin kolmea eri vaihtoehtoista verkkotekniikkaa: kytkintekniikkaa, reititintekniikkaa ja MPLS-tekniikkaa. Vertailun perusteella valitulla verkkotekniikalla tehtiin suunnitelma avoimesta, valmistajasta riippumattomasta standardeihin perustuvasta yritystason Ethernet-pohjaisesta TCP/IP prosessiverkkoratkaisusta. Johtopäätöksissä pohditaan valitun ratkaisun käytettävyyttä, tietoturvaa sekä toimenpiteitä niiden kehittämiseksi.

Histoire des religions et constructivisme. La religion comme 'technique'

(Résumé de l'ouvrage) Qu'est-ce qui justifie l'emploi de rituels dans de nombreuses civilisations, anciennes ou contemporaines ? Sur quoi repose l'efficacité des rites ? Pour répondre à ces questions, ce livre propose une approche transdisciplinaire novatrice, qui rompt avec le cloisonnement en champs scientifiques étanches prévalant trop souvent dans l'exploration des pratiques rituelles. La réflexion autour des frontières et interactions entre les sphères socioculturelle, psychique et physiologique fait ressortir le caractère plastique et dynamique de celles-ci. Il s'agit notamment de souligner l'importance, dans de nombreuses cultures et à des épo-ques différentes, de techniques ou « orthopratiques » corporelles, psychologiques et sociales utilisées en vue de résultats pratiques spécifiques. Par ailleurs, les discours et les « représentations » propres aux systèmes institutionnels (science, médecine, philosophie, théologie) sur lesquels repose notre culture moderne se révèlent à même d'effectuer la « construction-réalisation » des objets mêmes qu'ils prétendent décrire. Ainsi, tant les « orthopratiques » appliquées, traitées dans la première partie du volume, que les pratiques émanant de nos systèmes institutionnels, traitées dans la seconde partie, tendent vers des objectifs transformationnels et opératoires. Alors que les unes opèrent dans un cadre magico-religieux, thérapeutique ou pédagogique, les autres se situent dans le contexte de la modernité. Mais elles se rejoignent en une dynamique dont les contribu-tions réunies ici viennent éclairer la nature et l'homme aux niveaux organique, psychique et historico-social. Ce qui revient, du même coup, à relancer l'interrogation philosophique qui porte sur la notion même de « réalité ».