Nanoscale pores introduced into paper via mesoporous silica coatings using sol-gel chemistry.

Mesopores, with diameters between 2 and 50 nm, not only increase the specific surface area, but also generate hierarchically porous materials with specific properties such as capillary fluid transport, ion specific pore accessibility, or size exclusion. Paper is a strongly hierarchical, porous material with specific properties, such as capillary force-driven fluid transport. However, paper fibers change their morphology during the initial step of wood disintegration. This results in changes of the porous fiber structure. In particular paper fibers loose their mesopores during the final drying step in the fabrication process. Here, we investigate silica mesopore formation in paper by sol-gel chemistry and evaporation induced self-assembly to specifically introduce and rationally design mesopore formation and distribution in cotton linter and eucalyptus sulfate paper sheets. We demonstrate the importance of synchronizing the solvent evaporation rate and capillary fluid velocity to ensure mesopore formation as well as the influence of the fiber type and sol-gel solution composition. The combination of argon and krypton sorption, SAXS, TEM and CLSM provides systematic analysis of the porous structure and the silica distribution along the cellulose paper fiber length and cross-section. These results provide a deeper understanding of mesopore formation in paper and how the latter is influenced by paper fluidic properties.

Diagnosing water content in paper by terahertz radiation.

We explore the application of terahertz spectroscopic techniques for the remote determination of the water content of paper. The aim is the development of a rapid diagnostic imaging tool applicable in paper fabrication processes. THz radiation offers a high sensitivity for water, a good spatial resolution, and insensitivity to scattering at the paper surface. The advent of THz cameras makes fast large-area image detectors feasible. In this paper, we show for the case of a 0.6-THz fixed-frequency system, that the water content of paper can be determined with high accuracy. We demonstrate a quantitative (calibrated) method for determining the moisture content in paper based on extinction and phase measurements in the lower THz range with a spatial resolution in the mm-range and scanning times below two minutes.

Effluent-free papermaking: industrial experiences and latest developments in the German paper industry.

Thanks to multiple recirculation of process water, the German paper industry has succeeded in decreasing the specific fresh water demand from an average of 50 m3/t thirty years ago to 13 m3/t today. Although the increasing closure of white water loops creates many problems, it is bound to be part of the German paper industry's ongoing development. For a few years, in the production of packaging paper, two paper mills have been running with a totally closed water system including different process water treatment plants as 'kidneys'. This paper presents a comprehensive survey of the pros and cons of closed process water systems followed by significant examples of effluent-free production of corrugating medium and test liner. Additionally, operation experiences and economic aspects are discussed.

Comparison of the endocrine effects of treated wastewaters from different paper mills by use of an in-vitro test with modified yeast cells.

As opposed to effluents from chemical pulp production, very little is known about the endocrine potential of papermaking effluents. To evaluate the endocrine potential of biologically treated effluents from the main grades produced in Germany (fine, graphic and packaging papers), 16 samples were studied by means of the Recombinant Yeast Estrogen Assay (R-YEA). 10 samples were tested positive; seven of them were effluents from recovered paper processing mills. Possible sources of endocrine disruptors in addition to wood components include papermaking chemicals, paper converting chemicals, if recovered paper is used, and/or detrimental substances introduced by impurities in these chemicals. Six of the above samples were subjected to individual substance analyses to detect endocrinologically active or potentially endocrinologically active substances. Even though phthalate compounds were detected in concentrations between 0.46 and 2.36 microg/L, only two of the six samples were tested positive in the R-YEA, because the test fails to adequately detect this compound's class. Despite this drawback, the R-YEA will be used for further studies because of the great variety of potential endocrine substances present in paper mill effluents. In particular, mechanical and recycled fibre pulps as well as the constituents of chemical additives must be investigated in more detail.

The "fairy ring": a new radiographic finding in sarcoidosis.

A patient who had the "fairy ring" finding shows another new radiographic presentation of pulmonary sarcoidosis that clinicians can add to the list of signs of the disease.

"Tower vertebra": a new observation in sickle cell disease.

BACKGROUND: Skeletal abnormalities are common in sickle cell anemia. Ischemia, infarction, and growth disturbance of the thoracic and lumbar vertebral bodies are among the most common abnormalities, and can suggest the diagnosis radiographically. DESIGN AND PATIENTS: We recently encountered two adult patients in whom vertebrae had grown abnormally in height adjacent to infarcted short vertebrae. We then reviewed the thoracic and lumbar spine radiographs of 54 more adult patients with sickle cell anemia. RESULTS AND CONCLUSION: A total of eight patients (14%) displayed infarcted vertebrae with compensatory vertical growth of at least one adjacent vertebrae. These resemble the elongated vertebral bodies associated with other conditions. We can find no prior report of this finding in association with sickle cell anemia.

Symptomatic spinal calcinosis in systemic sclerosis (scleroderma).

Two patients with diffuse cutaneous systemic sclerosis and spinal calcification, involving the lumbar spine in one and the cervical spine in the other, are described. Computed tomography-guided aspiration of the calcific masses was performed, and material aspirated from one patient was shown to be apatite, Ca5(PO4)3OH. One patient showed improvement following lumbar laminotomy, hemilaminectomy, and diskectomy.

Is there an anatomic explanation for chest pain in patients with pulmonary sarcoidosis?

BACKGROUND: Chest pain (CP), its cause unknown, is a common and often prominent symptom of sarcoidosis. METHODS: We determined the frequency and character of CP in patients with pulmonary sarcoidosis and examined its relationship with (1) length of time since diagnosis, (2) roentgenograhic stage, and (3) radiographic abnormalities on spiral chest computed tomography (CT). RESULTS: Twenty-two patients were studied: 14 of 22 patients (64%) had CP, with 4 of 14 (29%) identifying pain as their primary symptom. Eleven of 14 (79%) had pleuritic CP; 12 of 22 (54.5%) described CP as substernal; and 5 of 22 (22.7%) described CP between the scapula. There was not a significant correlation between CP and the presence or degree of lymphadenopathy. There was no significant correlation between CP and the presence or location of pleural disease. Abnormalities of other thoracic structures also had no significant correlation with the presence of CP. CONCLUSIONS: We conclude that there is no "anatomic reason" for CP in patients with pulmonary sarcoidosis that is evident on chest CT.

Endobronchial cockroach: an unusual foreign body aspiration.

Foreign-body aspiration is a frequent and potentially lethal occurrence in children. It is associated with a variety of symptoms including choking, coughing, and wheezing. These symptoms differ in severity and are sometimes absent, and chest radiograph findings are often nonspecific. Thus, the diagnosis of foreign body aspiration is occasionally missed or delayed. A multitude of aspirated objects have been reported in the literature. In the present report, we describe the aspiration of a cockroach by a child with a delay in diagnosis of 3 d.

Intracranial placement of a nasotracheal tube after facial fracture: a rare complication.

Extensive facial trauma is often associated with fractures to the skull base, cribriform plate, and sphenoid sinus. Attempted intubation of patients with facial trauma may result in intracranial penetration and placement of nasogastric or nasotracheal tubes into the brain. Such a complication carries significant morbidity and mortality. Intracranial placement of nasogastric tubes has been reported multiple times in the literature. Intracranial placement of a nasotracheal tube, however, has been reported only twice. Such a case is presented, along with a review of the literature and a discussion.

Translational injuries in posterior elbow dislocation.

We describe a new plain radiographic finding in posterior elbow dislocation: a defect in the nonarticular posterior surface of the capitellum caused by impaction of the radial head during dislocation. The defect was visible on a lateral view unobscured by overlying bony structures in the unreduced state and confirmed on both an axial view after reduction and by magnetic resonance imaging. We propose that this lesion is analogous to the Hill-Sachs/Bankart lesion complex seen in translational glenohumeral injury.

Multicentric Castleman's disease: imaging findings.

Multicentric Castleman's disease is an unusual lymphoproliferative lesion typically associated with systemic manifestations and specific histopathology. We describe two cases of pathologically proven multicentric Castleman's disease along with radiographic and ultrasonographic findings.

Pseudostripe sign in lobar collapse.

The stripe sign in perfusion lung scanning refers to an area of focal hypoperfusion that fails to extend to the pleural surface, leaving a peripheral rim of perfused parenchyma. Although experimental evidence suggests that the stripe sign is caused by central pulmonary emphysema, we report a case of an identical perfusion defect related to a completely collapsed left lower lobe. This etiology should be considered in the differential diagnosis of the stripe sign.

Pseudo fracture of a defibrillating lead.

Routine follow-up chest X ray of several patients with the Endotak transvenous pacing lead suggested fracture of the conductor at the distal end of the proximal defibrillating coil. Electrical evaluation of these patients' leads demonstrated them to be working normally. Multiple x-ray views of a new undamaged lead demonstrated that in some projection the Endotak lead may appear fractured in spite of normal continuity of the conductors. Physicians dealing with these patients should be aware of this confusing x-ray finding.

Multiple symmetrical lipomatosis: computed tomographic appearance.

In a case of localized multiple symmetrical lipomatosis (Madelung's disease), we examined the cervical fat accumulation by computed tomography. We describe the radiographic features of this process and briefly review the pathophysiology of this rare disorder.

Acquired microileum: a companion to microcolon?

Acquired microcolon results from a lack of distension by the fecal stream because of a proximal obstruction or diversion. We report a case of acquired microileum, which we believe resulted from a similar mechanism, that is, lack of distension by the intestinal fluid column after a proximal ileal diversion.

Communicating intrathoracic hydrocele.

Tense ascites may cause herniation of parietal peritoneal reflection into the mediastinum at the gastroesophageal junction. This may produce a mass visible on chest radiograph and computed tomography (CT). This communicating intrathoracic hydrocele may occur in the absence of hiatal hernia and may be confused with other middle mediastinal fluid collections including necrotic tumor, abscess, cyst of foregut origin, or pancreatic pseudocyst. Recognition of this entity in patients with ascites should prevent diagnostic confusion and unnecessary further evaluation.

High resolution computed tomography in early scleroderma lung disease.

Seventeen patients with early systemic sclerosis (SSc) underwent high resolution computed tomography (HRCT) of the chest to evaluate dyspnea and/or abnormal pulmonary function tests (PFT). All patients were assigned a dyspnea score and each had routine chest radiography (CXR). Bronchoalveolar lavage (BAL) was performed on 10 patients. HRCT was abnormal in 15 patients (88%), while CXR was abnormal in only 10 patients (59%). Mediastinal lymphadenopathy was detected in 7 patients (41%). Disease duration, dyspnea score, and forced vital capacity (FVC) did not correlate with HRCT score. However, trends toward higher total BAL cell counts and higher BAL neutrophil counts were noted in patients with ground glass opacities on HRCT, and BAL lymphocyte counts were significantly higher in such cases. HRCT is superior to CXR for detecting early interstitial lung disease in SSc, but patient history and FVC correlate poorly with HRCT findings. Ground glass opacities on HRCT may reflect active alveolitis, and mediastinal lymphadenopathy associated with SSc lung disease may be a consequence of pulmonary inflammation.