Synergies between Fibrillated Nanocellulose and Hot-Pressing of Papers Obtained from High-Yield Pulp

To extend the application of cost-effective high-yield pulps in packaging, strength and barrier properties are improved by advanced-strength additives or by hot-pressing. The aim of this study is to assess the synergic effects between the two approaches by using nanocellulose as a bulk additive, and by hot-pressing technology. Due to the synergic effect, dry strength increases by 118% while individual improvements are 31% by nanocellulose and 92% by hot-pressing. This effect is higher for mechanical fibrillated cellulose. After hot-pressing, all papers retain more than 22% of their dry strength. Hot-pressing greatly increases the paper's ability to withstand compressive forces applied in short periods of time by 84%, with a further 30% increase due to the synergic effect of the fibrillated nanocellulose. Hot-pressing and the fibrillated cellulose greatly decrease air permeability (80% and 68%, respectively) for refining pretreated samples, due to the increased fiber flexibility, which increase up to 90% using the combined effect. The tear index increases with the addition of nanocellulose, but this effect is lost after hot-pressing. In general, fibrillation degree has a small effect which means that low- cost nanocellulose could be used in hot-pressed papers, providing products with a good strength and barrier capacity.

On-Site X-ray Fluorescence Spectrometry Measurement Strategy for Assessing the Sulfonation to Improve Chemimechanical Pulping Processes

Minimizing the fiber property distribution would have the potential to improve the pulp properties and the process efficiency of chemimechanical pulp. To achieve this, it is essential to improve the level of knowledge of how evenly distributed the sulfonate concentration is between the individual chemimechanical pulp fibers. Due to the variation in quality between pulpwood and sawmill chips, as well as the on-chip screening method, it is difficult to develop an impregnation system that ensures the even distribution of sodium sulfite (Na₂SO₃) impregnation liquid. It is, therefore, crucial to measure the distribution of sulfonate groups within wood chips and fibers on a microscale. Typically, the degree of unevenness, i.e., the amount of fiber sulfonation and softening prior to defibration, is unknown on a microlevel due to excessively robust or complex processing methods. The degree of sulfonation at the fiber level can be determined by measuring the distribution of elemental sulfur and counterions of sulfonate groups, such as sodium or calcium. A miniaturized energy-dispersive X-ray fluorescence (ED-XRF) method has been developed to address this issue, enabling the analysis of sulfur distributions. It is effective enough to be applied to industrial laboratories for further development, i.e., improved image resolution and measurement time.

Lignin Inter-Diffusion Underlying Improved Mechanical Performance of Hot-Pressed Paper Webs

Broader use of bio-based fibres in packaging becomes possible when the mechanical properties of fibre materials exceed those of conventional paperboard. Hot-pressing provides an efficient method to improve both the wet and dry strength of lignin-containing paper webs. Here we study varied pressing conditions for webs formed with thermomechanical pulp (TMP). The results are compared against similar data for a wide range of other fibre types. In addition to standard strength and structural measurements, we characterise the induced structural changes with X-ray microtomography and scanning electron microscopy. The wet strength generally increases monotonously up to a very high pressing temperature of 270 °C. The stronger bonding of wet fibres can be explained by the inter-diffusion of lignin macromolecules with an activation energy around 26 kJ mol^-1 after lignin softening. The associated exponential acceleration of diffusion with temperature dominates over other factors such as process dynamics or final material density in setting wet strength. The optimum pressing temperature for dry strength is generally lower, around 200 °C, beyond which hemicellulose degradation begins. By varying the solids content prior to hot-pressing for the TMP sheets, the highest wet strength is achieved for the completely dry web, while no strong correlation was observed for the dry strength.

Unique steel belt press technology for high strength papers from high yield pulp

The dry strength properties of hot-pressed moist paper improved as stiff high-yield pulp fibers soften and the sheet density increased. Very high wet strength was also achieved without adding strengthening agents. This research focuses on a new hot-pressing methodology based on a steel belt-based pilot cylinder press with infrared heating. The heated steel belt transports the moist paper into the cylinder nip with two adjacent steel rollers with adjustable nip pressure. The temperature ranges up to 300 °C, maximum speed is 5 m/min, maximum pulling force from the steel belt is 70 kN and the line load in the two press nips is 15 kN/m each. High peak pressures are possible due to the hard press nip between steel rolls and steel belt, allowing a good heat transfer to the paper. The long dwell time allows strained drying of the paper which results to high density and high wet strength. Paper samples from high-yield pulps were tested at different nip pressures, temperatures and machine speeds while the dry content was kept constant at about 63%. High nip pressure showed the largest effect on densification and dry strength. While high temperature and long dwell time seem to be most important in achieving high wet strength.

A sustainable strategy for production and functionalization of nanocelluloses

A sustainable strategy for the neat production and surface functionalization of nanocellulose from wood pulp is disclosed. It is based on the combination of organocatalysis and click chemistry (“organoclick” chemistry) and starts with nanocellulose production by organic acid catalyzed hydrolysis and esterification of the pulp under neat conditions followed by homogenization. This nanocellulose fabrication route is scalable, reduces energy consumption and the organic acid can be efficiently recycled. Next, the surface is catalytically engineered by “organoclick” chemistry, which allows for selective and versatile attachment of different organic molecules (e.g. fluorescent probes, catalyst and pharmaceuticals). It also enables binding of metal ions and nanoparticles. This was exemplified by the fabrication of a heterogeneous nanocellulose-palladium nanoparticle catalyst, which is used for Suzuki cross-coupling transformations in water. The disclosed surface functionalization methodology is broad in scope and applicable to different nanocelluloses and cellulose based materials as well.

Sustainable Design for the Direct Fabrication and Highly Versatile Functionalization of Nanocelluloses

This study describes a novel sustainable concept for the scalable direct fabrication and functionalization of nanocellulose from wood pulp with reduced energy consumption. A central concept is the use of metal-free small organic molecules as mediators and catalysts for the production and subsequent versatile surface engineering of the cellulosic nanomaterials via organocatalysis and click chemistry. Here, "organoclick" chemistry enables the selective functionalization of nanocelluloses with different organic molecules as well as the binding of palladium ions or nanoparticles. The nanocellulosic material is also shown to function as a sustainable support for heterogeneous catalysis in modern organic synthesis (e.g., Suzuki cross-coupling transformations in water). The reported strategy not only addresses obstacles and challenges for the future utilization of nanocellulose (e.g., low moisture resistance, the need for green chemistry, and energy-intensive production) but also enables new applications for nanocellulosic materials in different areas.

[Organisation of palliative care in and outside hospital]

Patients with advanced, incurable disease need easy access to qualified care. Basic palliative care should be provided in all clinical hospital departments and in community care. In addition, palliative care units in hospitals and nursing homes, and ambulatory, multidisciplinary, palliative care teams have a supportive role by providing teaching, advice, and care, also in primary care. The regional palliative care centres in university hospitals are important centres for research, skills building, and developmental work, in addition to the management of the most complex patients. Palliative care requires much collaboration, and the general practitioner has an important role. In addition, hospital-based palliative care teams are important bridges between the different levels of the health care system. The Norwegian Standard for Palliative Care gives recommendations for the organisation of palliative care at all levels, and forms the basis for this article.

Zygoma fixture in the management of advanced atrophy of the maxilla: technique and long-term results

Despite refinements in surgical technique, including bone grafting and sophisticated prosthetic reconstructions, there are limitations to what can be achieved with bone-anchored fixed prostheses in patients with advanced atrophy of the maxillae. A new approach was suggested by a long-term study on onlay bone grafting and simultaneous placement of a fixture based on a new design: the zygoma fixture, and the aim of this study was to assess its potential. Twenty-eight consecutive patients with severely resorbed edentulous maxillae were included, 13 of whom had previously had multiple fixture surgery in the jawbone that had failed. A total of 52 zygoma fixtures and 106 conventional fixtures were installed. Bone grafting was deemed necessary in 17 patients. All patients have been followed for at least five years, and nine for up to 10 years. All patients were followed up with clinical and radiographic examinations, and in some cases rhinoscopy and sinoscopy as well. Three zygoma fixtures failed; two at the time of connection of the abutment and the third after six years. Of the conventional fixtures placed at the time of the zygoma fixture, 29 (27%) were lost. The overall prosthetic rehabilitation rate was 96% after at least five years of function. There were no signs of inflammatory reaction in the surrounding antral mucosa. Four patients with recurrent sinusitis recovered after inferior meatal antrostomy. To conclude, the zygoma fixture seems to be a valuable addition to our repertoire in the management of the compromised maxilla.

Breakthrough pain characteristics and syndromes in patients with cancer pain. An international survey

Breakthrough pain (BKP) is a transitory flare of pain that occurs on a background of relatively well controlled baseline pain. Previous surveys have found that BKP is highly prevalent among patients with cancer pain and predicts more severe pain, pain-related distress and functional impairment, and relatively poor quality of life. An international group of investigators assembled by a task force of the International Association for the Study of Pain (IASP) evaluated the prevalence and characteristics of BKP as part of a prospective, cross-sectional survey of cancer pain. Fifty-eight clinicians in 24 countries evaluated a total of 1095 patients with cancer pain using patient-rated items from the Brief Pain Inventory (BPI) and observer-rated measures. The observer-rated information included demographic and tumor-related data, the occurrence of BKP, and responses on checklists of pain syndromes and pathophysiologies. The clinicians reported BKP in 64.8% of patients. Physicians from English-speaking countries were significantly more likely to report BKP than other physicians. BKP was associated with higher pain scores and functional interference on the BPI. Multivariate analysis showed an independent association of BKP with the presence of more than one pain, a vertebral pain syndrome, pain due to plexopathy, and English-speaking country. These data confirm the high prevalence of BKP, its association with more severe pain and functional impairment, and its relationship to specific cancer pain syndromes. Further studies are needed to characterize subtypes of BKP. The uneven distribution of BKP reporting across pain specialists from different countries suggests that more standardized methods for diagnosing BKP are needed.

Prospective follow-up study of 95 patients with edentulous mandibles treated according to the Brånemark Novum concept

BACKGROUND

The long-term predictability reported with the traditional two-staged Brånemark method has led to developments aimed at simplifying the technique and reducing healing time. Results from a pilot study using the Brånemark Novum concept are promising, and it has been shown possible to fabricate and deliver an implant-supported fixed prosthesis to the patient on the day of surgery.

PURPOSE

The objective of this study is to report clinical and radiographic outcomes in a group of patients treated according to the Brånemark Novum concept.

MATERIALS AND METHODS

Ninety-five patients with edentulous mandibles were consecutively included in the study. Three specially designed fixtures were placed in each patient (285 fixtures in total) using drilling templates. The fixtures were immediately splinted with a prefabricated substructure, and fixed prostheses were delivered the same day in 67% of the patients. For the rest, prosthesis delivery ranged from 1 to 40 days (mean 5.6 d). Clinical and radiographic examinations were performed after 3 months, 6 months, 1 year, and then annually. The follow-up time was 1 to 5 years (mean 2.5 yr).

RESULTS

The cumulative prosthesis survival rate was 99%. Eighteen fixtures (6.3%) failed in 13 patients. Kaplan-Meier survival estimates demonstrated a probability implant survival at 1 year of 95.0% (94 patients), at 3 years of 93.3% (47 patients), and at 5 years of 93.3% (9 patients). The mean bone loss was 0.73 mm between the examinations at 3 months and 1 year, 0.16 mm during the second year, and 0.13 mm annually during years 3 to 5.

CONCLUSIONS

Comparable results, related to continuous prosthesis stability, were shown for the Novum approach compared with the traditional two-staged procedure. Survival of individual fixtures is lower when immediate loading is applied.

Edentulousness and oral rehabilitation: experiences from the patients' perspective

The psychological effects of tooth loss in the permanent dentition are relatively unknown. Complete edentulousness is a serious life event in terms of readjustment. The aim of the study was to describe the process patients with deteriorating dental status had gone through before treatment with a fixed prosthesis (Brånemark System, Novum), and to describe what living with a fixed prosthesis means to the patients themselves. In-depth interviews were carried out with 18 patients, and the interviews were transcribed verbatim and analysed in open, axial and selective coding processes according to Grounded Theory. In the analysis, four categories were developed and labelled: 'alterations in self-image', 'becoming a deviating person', 'becoming an uncertain person' and 'becoming the person I once was'. 'Alterations in self-image' was identified as the core category and was related to the other three categories. The core category describes the changes in self-image starting with the subjects' increasingly worsened dental status, followed by a period of them having to live and cope with a denture and, finally, their living with a fixed prosthesis. The motive power for the decision to undergo treatment with a fixed prosthesis seems to be a desire to restore dental status and also to recapture attractiveness, self-esteem and a positive self-image.

Brånemark Novum: prosthodontic and dental laboratory procedures for fabrication of a fixed prosthesis on the day of surgery

PURPOSE

The purpose of this report is to describe a new technique to fabricate and deliver an implant-supported fixed prosthesis to the patient on the day of surgery, and to propose a protocol for the prosthodontic and dental laboratory procedures.

MATERIALS AND METHODS

The development of the Brånemark Novum prosthodontic protocol is reviewed, and clinical and dental laboratory assessments and methods are described.

RESULTS

The total treatment time to fabricate a permanent implant-supported fixed prosthesis in the mandible can be reduced to 1 day with the Brånemark Novum technique. The new method includes a precise surgical technique using drilling templates for predetermined implant positions, a rigid splinting of the implants immediately after placement, the use of a prefabricated titanium framework, and elimination of implant impression procedures.

CONCLUSION

With the technique described in this report, it is possible to provide patients with a permanent implant-supported fixed prosthesis in the mandible on the day of implant surgery. Patient benefits are obvious, with drastically reduced total treatment time, lower cost, and fewer clinical visits.

Brånemark Novum: a new treatment concept for rehabilitation of the edentulous mandible. Preliminary results from a prospective clinical follow-up study

BACKGROUND

Brånemark fixtures were originally prescribed to be placed in two surgical stages. During the past years, reports on the placement of machined titanium implants in a one-stage procedure have been published, and the results have been encouraging. Recently there has been considerable interest in early or immediate loading.

PURPOSE

The purpose of this article is to report the preliminary clinical results of a new method for implant treatment of the edentulous mandible. The new protocol involves prefabricated components and surgical guides, elimination of the prosthetic impression procedure and attachment of the permanent fixed bridge on the day of implant placement.

METHODS

Fifty patients (26 males, 24 females) received 150 Brånemark Novum implants and were followed from 6 months to 3 years after implant placement. Bone width and height were determined preoperatively with the use of radiographs. The jaw was reduced in height to accommodate three special 5-mm wide implants. Precise implant positioning was accomplished with special drilling templates. Drill guides were placed over the drilling templates during site preparation using a series of specially designed drills. After the mucosa had been sutured back into position, a prefabricated titanium lower bar was connected with titanium screws to the transmucosal fixture. Another titanium bar was then attached by the prosthodontist, and a bite registration was performed. The bridge was attached to the upper bar. The permanent reconstruction was provided to the patient later the same day.

RESULTS

Three implants were lost to follow-up and three failed, resulting in an overall survival rate of 98%. One prosthesis failed, leaving a prosthetic survival rate of 98%. The average treatment time was approximately 7 hours. At the baseline examination, the marginal bone level was 0.72 mm below the reference point. The average marginal bone loss was 0.2 mm per year and 0.26 mm between the 3-month and 1-year control visits. The accumulated mean bone loss, including baseline, was -1.25 mm. A patient questionnaire demonstrated that 94% of the patients did not experience any discomfort during treatment and all patients would recommend the procedure to others.

CONCLUSION

The results of this study indicate that the precise surgical and prosthetic protocol allows successful prosthetic rehabilitation of mandibular edentulism and that the permanent reconstruction can be provided to the patient on the day of fixture surgery.