Delignification and Bleaching Response of Earlywood and Latewood

Abstract

The delignification response in cooking and the impact of bleaching on earlywood and latewood were studied. Spruce earlywood and latewood chips were pulped by the kraft process and subsequently treated with one bleaching chemical at a time. In cooking, latewood required a higher alkali charge to reach the same kappa number. No difference in the light absorption coefficient between the different fiber types was observed. After oxygen delignification the earlywood fibers had a higher light absorption coefficient at the same kappa number. The difference in light absorbing material was maintained when bleaching was performed with chlorine dioxide, ozone, and peracetic acid. Hydrogen peroxide decreased the light absorbing structures in the earlywood to the same level as for latewood. The earlywood pulp had a higher brightness at a given kappa number than the latewood. The higher brightness remained through all bleaching operations and was primarily due to a higher light scattering ability.     

A review of 716 consecutive free flaps for oncologic surgical defects: refinement in donor-site selection and technique

Free-tissue transfer has become an important method for reconstructing complex oncologic surgical defects. This study is a retrospective review of a 10-year experience with 716 consecutive free flaps in 698 patients. Regional applications included the head and neck (69 percent), trunk and breast (14 percent), lower extremity (12 percent), and upper extremity (5 percent). Donor sites included the rectus abdominis (195), fibula (193), forearm (133), latissimus dorsi (69),jejunum (55), gluteus (28), scapula (26), and seven others (17). Microvascular anastomoses were performed to large-caliber recipient vessels using a continuous suture technique; end-to-end anastomoses were preferred (75 percent). Flaps were designed to avoid the need for vein grafts. Conventional postoperative flap monitoring methods were used. These included clinical observation supplemented by Doppler ultrasonography, surface temperature probes, and pin prick testing. Buried flaps were either evaluated with Doppler ultrasonography or not monitored. The overall success rate for free-flap reconstruction of oncologic surgical defects was 98 percent. Fifty-seven flaps (8 percent) were reexplored for either anastomotic or infectious problems. Reexplored flaps were salvaged in 40 cases (70 percent). Surviving flaps resulted in a healed wound and did not delay postoperative radiation or chemotherapy. The incidence of major and minor postoperative complications was 34 percent. The mean duration of hospitalization was 20 days, and the average cost was $40,224. The results of this study support the need for only seven donor sites to solve the majority (98 percent) of oncologic problems requiring microsurgical expertise. The evolution of preferred donor sites for specific regional applications is illustrated in this 10-year experience. Technical refinements have simplified performing the microsurgical anastomoses and essentially eliminated the need for vein grafts. Conventional monitoring has led to the rapid identification of vascular compromise and subsequent flap salvage in the majority of non-buried free flaps.     

Separate Bleaching of Pulp Fractions Enriched in Earlywood and Latewood Fibers

Abstract

Unbleached softwood kraft pulp was fractionated in hydrocyclones into a fine fraction, enriched in earlywood fibers, and a coarse fraction, enriched in latewood fibers. The response to individual bleaching chemicals and the bleachability in bleaching sequences of the pulp fractions was studied.

The light absorption coefficient, light scattering coeffient, and brightness were higher in the unbleached fine fraction than in the coarse fraction. Hydrogen peroxide managed to reduce the light absorption coefficient of the earlywood enriched fine fraction more efficiently than that of the latewood enriched fraction.

In the TCF‐sequence the light absorption coefficient of the fine fraction was reduced to the level of the coarse fraction at a given consumption of bleaching chemicals. In the ECF‐sequence the difference in light absorption coefficient remained between the fractions. At a given consumption of bleaching chemicals, the fine fraction had higher brightness than the coarse fraction, 2%‐ and 1%‐units on the ISO‐scale in the TCF and ECF bleaching sequence, respectively.     

Transverse glabellar flap for obliteration/isolation of the nasofrontal duct from the anterior cranial base

Management of fractures involving the nasofrontal duct region of the frontal sinus has focused on preserving function when possible or obliterating the sinus and duct when fracture patterns potentiate ductal obstruction and possible transcranial seeding of bacteria. When frontal sinus preservation is in doubt, controversy surrounds the use of cranialization versus obliteration, and the method of obliteration. Perioperative and late postoperative infections are uncommon, but their occurrence jeopardizes an often complex reconstruction and can be life threatening. This paper describes the design and indications for a pedicled transverse glabellar muscle flap for obliteration of the nasofrontal duct, thereby isolating the anterior cranial base from the aerodigestive system. This vascularized muscle flap utilizes the corrugator supercilii and procerus muscles, which are introduced into the sinus via a small, surgically created window in the superomedial orbital wall without disturbing the central facial aesthetic contours. Six patients with comminuted fractures at the nasofrontal duct level associated with displaced posterior frontal sinus fractures have been treated with the transverse glabellar flap. Follow-up ranges from 8 to 30 months. There have been no early or late postoperative complications. The transverse glabellar flap is a reliable and versatile method of partitioning the upper aerodigestive tract from the anterior cranial base with vascularized tissue, thus minimizing the risk of infectious complications. The resulting donor site deformity is more acceptable than that seen with the traditional pedicled galeal frontalis flap.     

The synthesis of multilayer graphene materials by the fluorination of carbon nanodiscs/nanocones

Multilayer carbonaceous nanomaterial has been synthesized using a two-step process: carbon nanodiscs/nanocones were fluorinated using either the direct reaction with pure F₂ gas or the thermal decomposition of solid fluorinating agent (TbF₄). Then the fluorinated parts were removed by treatment at 600 °C in air. When the fluorine atoms are homogenously dispersed, using fluorination by TbF₄, thinning due to thermal defluorination results in multilayer materials with 7–10 nm of thickness and 400–500 nm of width. Such resulting materials and the fluorinated precursors have been characterized by solid state NMR, TGA, XRD, SEM, TEM, AFM and Raman spectroscopy.     

The current role of preoperative arteriography in free fibula flaps

Parathyroid carcinoma is one cause of primary hyperparathyroidism, a condition in which there is hypercalcemia and dysregulated hypersecretion of PTH. In normal, and in some neoplastic parathyroid cells, PTH secretion is mediated by the cell surface calcium-sensing receptor. We describe the first therapeutic use of a novel molecule, a calcimimetic, that has agonist action at the calcium-sensing receptor. A 78-yr-old man with parathyroid carcinoma was admitted with hypercalcemia, markedly elevated PTH, and a change in mental status. He was treated for 17 days with conventional therapy, which included saline hydration, furosemide, pamidronate, and calcitonin. This was ineffective, and on hospital day 18, calcimimetic at a dose of 50 mg, orally, every 6 h was added. On hospital day 25, the dose was increased to 100 mg, orally, every 6 h, and on hospital day 30, saline and furosemide were discontinued. He was discharged on hospital day 40. With several dose adjustments, he has been treated with monotherapy calcimimetic for over 600 days and has not required any other interventions for his parathyroid carcinoma. Mean daily precalcimimetic treatment values of serum ionized calcium and PTH were 1.83 mmol/L and 872 pg/mL, respectively. During hospitalization, at the lower dose of calcimimetic, calcium and PTH decreased to 1.67 mmol/L and 538 pg/mL; with the higher dose they further decreased to 1.51 mmol/L and 444 pg/mL. Since discharge, and despite increasing levels of PTH, serum calcium has remained high, but lower than the admission level and acutely responsive to changes in calcimimetic doses. This compound, a calcimimetic, the first of a new class of compounds with activity at the calcium-sensing receptor, has been used to treat a patient with parathyroid carcinoma. During 2 yr of treatment, no adverse clinical effects have been observed, and it appears to have been effective at controlling hypercalcemia.     

Structural/textural properties and water reactivity of fluorinated activated carbons

Hydrophobic activated carbons are considered as interesting materials for air or water remediation due to their enhanced affinity for slightly water-soluble organic species. In this context, a commercial activated carbon, in an extruded form, was fluorinated under mild conditions (pure fluorine gas at room temperature) in order to decrease its hydrophilic character and to preserve its microporosity. For comparison, a hydrogenated activated carbon was also prepared by H₂ treatment. The resulting samples were characterised by various techniques in order to determine the evolution of the activated carbon materials in terms of composition (XPS, elemental analysis, TGA and NMR) and porosity (nitrogen physisorption (77 K), mercury intrusion and immersion calorimetry). For the fluorinated carbon, the nature of the CF_x groups and the strength of the C–F bonds were also investigated using ¹³C and ¹⁹F solid state NMR and TGA techniques. A labile character of the C–F bond, so far exclusively observed for fluorine intercalation compounds, is also shown for the first time for a fluorinated activated carbon by water adsorption/desorption isotherms at room temperature. Care should then be taken for its use in presence of water.     

The voice conveys specific emotions: Evidence from vocal burst displays.

Studies of emotion signaling inform claims about the taxonomic structure, evolutionary origins, and physiological correlates of emotions. Emotion vocalization research has tended to focus on a limited set of emotions: anger, disgust, fear, sadness, surprise, happiness, and for the voice, also tenderness. Here, we examine how well brief vocal bursts can communicate 22 different emotions: 9 negative (Study 1) and 13 positive (Study 2), and whether prototypical vocal bursts convey emotions more reliably than heterogeneous vocal bursts (Study 3). Results show that vocal bursts communicate emotions like anger, fear, and sadness, as well as seldom-studied states like awe, compassion, interest, and embarrassment. Ancillary analyses reveal family-wise patterns of vocal burst expression. Errors in classification were more common within emotion families (e.g., ’self-conscious,’ ’pro-social’) than between emotion families. The three studies reported highlight the voice as a rich modality for emotion display that can inform fundamental constructs about emotion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reconstruction of lateral skull base oncological defects: the role of free tissue transfer

The present study was performed to investigate the age-dependent changes in body composition and the possible role of growth hormone (GH), insulin-like growth factor (IGF)-I and IGF-binding protein-3 (IGFBP-3) in these changes in postmenopausal Japanese women. A total of 161 Japanese women aged 45-88 years (mean 62) were enrolled in the cross-sectional study. Body composition (bone mineral content (BMC), lean body mass (LBM) and fat) was measured by dual-energy X-ray absorptiometry, and the percentage of BMC, LBM and fat was calculated by dividing each absolute value of body composition by total body mass. Urinary GH concentration divided by creatinine in nocturnal urine samples collected just after waking was used as an index of endogenous GH secretion. Serum levels of IGF-I and IGFBP-3 were measured by RIA. Urinary GH levels as well as serum levels of IGF-I and IGFBP-3 declined with age. BMC, %BMC and LBM also declined with age, while fat mass and %fat did not obviously change with age. Urinary GH levels as well as serum levels of IGF-I and IGFBP-3 correlated positively with BMC, even if age was taken into account. On the other hand, urinary GH correlated negatively with fat and %fat. In contrast, serum levels of IGF-I and IGFBP-3 correlated positively with fat and %fat. LBM did not correlate with either urinary GH or serum IGFBP-3 levels but exhibited a weakly positive correlation with serum IGF-I level. The present study suggests that the GH-IGF-I-IGFBP-3 axis positively regulates bone mass, and that GH and IGF-I-IGFBP-3 inversely regulate fat mass, i.e. GH negatively and IGF-I-IGFBP-3 positively regulates it.