Development of superabsorbent soy protein-based bioplastic matrices with incorporated zinc for horticulture

BACKGROUND

The use of superabsorbent materials in horticulture has spread recently. These materials, which can retain water and release it as crops need it, have strong advantages such as the efficient use of water in periods of drought. However, these materials are made of synthetic polymers, which present problems of degradability and, sometimes, toxicity. For this reason, the main objective of this work is the development of biodegradable superabsorbent bioplastic (SAB) matrices using a soy protein isolate (SPI) as raw material. Zinc is also incorporated into these bioplastic matrices as an essential micronutrient for plants, to increase their added value.

RESULTS

The incorporation of zinc chelated with 2,2',2″,2‴-(Ethene-1,2-diyldinitrilo)tetraacetic acid (Zn EDTA) (a salt with which the micronutrient is incorporated) into soy protein-based bioplastic matrices improved their superabsorbent capacity and provided a controlled release of water and nutrients to the crops.

CONCLUSIONS

The results show the strong potential for the use of these bioplastic matrices in horticulture as superabsorbent materials that can release nutrients in a controlled manner. © 2019 Society of Chemical Industry.

Interfacial and oil/water emulsions characterization of potato protein isolates

Interfacial and emulsifying properties of potato protein isolate (PPI) have been studied to evaluate its potential application to stabilize oil/water emulsions at two pH values (2 and 8). The amount, type, and solubility of proteins and the size of aggregates have been determined in aqueous dispersion. Air-water and oil-water interfacial properties (adsorption, spreading, and viscoelastic properties) have been determined as a function of concentration and pH using soluble phases of PPI. The behavior of PPI stabilized oil/water emulsions has been then analyzed by droplet size distribution measurements and interfacial concentration. PPI exhibits low solubility over a wide range of pH values, with the presence of submicrometer aggregates. The pH value exerts a negligible effect on interfacial tension (oil-water) or surface pressure (air-water) but displays very important differences in viscoelastic properties of the interfacial films formed between oil and water. In this sense, pH 8 provides a major elastic response at oil-water interfaces as compared to pH 2. In relation with this result, a much higher ability to produce fine and stable emulsions is noticed at pH 8 as compared to pH 2. Consequently, there is an evident relationship between the rheological properties of the oil-water interfacial films and the macroscopic emulsion behavior.

Influence of Semicontinuous Processing on the Rheology and Droplet Size Distribution of Mayonnaise-like Emulsions

Oil-in-water (o/w) emulsions stabilized by egg yolk, with a composition similar to those found in commercial mayonnaises or salad dressings, were processed in a semicontinuous device. This specially designed emulsification device consists of, basically, a vessel provided with an anchor impeller, where the continuous phase was initially placed; a pumping system that controls the addition of the oily phase; a rotor-stator unit, where the major breaking of the oily droplets takes place, and a recirculation system. The design allowed the introduction of a rotational rheometer to obtain viscosity data along the emulsification process. The most important advantages of this in-line emulsification device, when compared to discontinuous emulsification equipment, are the possibilities of recording viscosity data along the process and the higher values for the storage, G', and loss moduli, G'', of the resulting emulsions. The influence of egg yolk concentration, agitation speed, and flow rate over the rheological properties (G', G'') as well as droplet size distribution were investigated. Higher protein concentration, agitation speed and flow rate generally produce emulsions with higher G' and G'' values.

[Cranial lesions due to forceps delivery]

Deliveries with forceps or vacuum-extraction increase the incidence of perinatal craneoencephalic lesions, for which reason cesarean sections are performed more frequently. We report 3 cases of cranial lesions due to forceps deliveries, 2 with depressed skull fractures and 1 with a depressed fracture and an associated epidural hematoma. Diagnosis is made on clinical and radiological founds with CT scan or MRI. Treatment is surgical and consists of elevation of the depressed fracture and evacuation of the hematoma. The correct use of forceps is very important to avoid this kind of lesions in the newborn, especially in cases of difficult delivery.

[Childhood spinal tumours]

We report a large series of 48 childhood spine tumors diagnosed and treated at our Hospital between 1986 and 2006. Spinal tumors in children are a rare and heterogeneous condition that frequently are diagnosed late because of their uncharacteristic clinical picture. Symptoms are usually limited to diffuse back pain or spinal deformities, prior to leg paresis or sphincter dysfunction. Diagnosis is usually made with MRI or CT. Treatment is surgical in most cases. The prognosis is variable due to the diverse histological findings and it may require the use of complementary treatments as chemotherapy or radiation.

[Brain-stem tumors in children]

We report a large series of brain-stem tumors seen during 18 years of at our hospital. We diagnosed and treated a total of 42 patients between 1988 and 2006; 36 of them were operated with partial resection in most cases. Brain-stem tumors constitute a rare condition with very bad prognosis. A surgical complete resection of the mass is not possible in most cases, so the principal surgical objective is reduction and decompression. The best prognosis is seen in patients with low grade tumors with minimal neurologic deficit. Most of these tumors cause death in a short period, usually one year or less.

Pediatric giant cell glioblastoma: a case report and review of the literature

INTRODUCTION

Giant cell glioblastoma is a subtype of glioblastoma multiforme (GM) whose most characteristic histology is the presence of plentiful multinucleated giant cells. These tumours are very rare and account for only 5% of GM. They do not have specific localization, although normally they are supratentorial and affect mostly the temporal lobe. They may occur at any age, but mostly they occur in younger people than GM. They are infrequent in childhood, but they have longer survival in paediatric age.

CASE REPORT

We present an 11-year-old girl that was operated but whose tumour recurred in a month after apparent total removal.

DISCUSSION

We review in the literature the clinical, histological, immuno-histochemical and genetic characteristics, as well the prognosis of this tumour.

[Subdural hematoma associated with arachnoid cyst]

We describe 3 young patients with history of mild cranial trauma who presented the rare association of subdural hematoma and arachnoid cyst. Clinical and radiological signs are reviewed.

Meningioangiomatosis: advanced imaging and pathological study of two cases

Meningioangiomatosis (MA) is a rare benign intracranial tumour of uncertain pathogenesis, with only 33 cases reported in the literature. Imaging features have been described in 21 cases, only 3 with contrast-enhanced MRI. We present two cases of MA with MRI and/or CT findings and gross, ultrastructural, and immunohistochemical characteristics. MRI is particularly helpful for establishing the origin of the lesion and its anatomical location, while CT shows calcification, if present. The pathological characteristics establish the diagnosis and underline the differences from other entities such as malignant meningioma, one of the most important differential diagnostic considerations.

Extradural hematoma: analysis of factors influencing the courses of 161 patients

The clinical and computed tomographic (CT) findings in a series of 161 consecutive patients operated upon for postraumatic extradural hematoma are analyzed. Thirteen (8%) patients had delayed epidural hematoma formation. The overall mortality for the series was 12%, significantly lower than that observed during the prior "angiographic" period at the same unit (30%). Because all but 1 of the deaths occurred among the 66 patients unconscious at the time of operation (27% mortality in this subgroup), the authors sought differential factors between comatose and noncomatose patients at operation. There were no significant differences between these groups in age, sex, mechanism of injury, preoperative course of consciousness (lucid interval or not), or epidural hematoma location and shape. In contrast, significant differences were seen between the two subgroups in trauma-to-operation interval, hematoma volume, CT hematoma density (mixed low-high CT density vs. homogeneous hyperdensity), midline displacement, severity of associated intracranial lesions, and postoperative intracranial pressure (ICP). Patients comatose at operation usually evidenced a more rapid clinical deterioration (a shorter trauma-to-operation interval) and tended to have a large hematoma volume, a higher incidence of mixed CT density clot (hyperacute bleeding), more marked shift of midline structures, more severe associated lesions, and higher postoperative ICP levels.

Cerebral hemisphere swelling in severe head injury patients

The clinical course and the intracranial pressure (ICP) changes in 66 severe head injury patients presenting bulk enlargement of one cerebral hemisphere within a few hours of trauma have been analyzed. These patients represent 11% of a series of 589 severe head injury cases studied with computerized tomography (CT). Cerebral hemisphere swelling, which was associated with an ipsilateral subdural haematoma of variable extent in 58 patients (88%), or a large epidural haematoma in 5 patients (7%), and occurred as an isolated lesion in 3 patients (4%), carried the highest incidence of uncontrollable intracranial hypertension, the highest mortality rate and the shortest survival period after trauma in the authors' severe head injury series. The high incidence of arterial hypotension and/or hypoxaemia at admission (48% of cases), and the severity of clinical presentation (82%) of patients scored 5 patients or less in the Glasgow Coma Scale, 77% had uni- or bilateral mydriasis and 82% initial ICP above normal limits) correlated with the very poor final outcome (85% mortality). Only one of the 12 patients with normal initial ICP continued to have low pressure throughout the course. High dose thiopental failed to control severe intracranial hypertension in 29 patients (44%) who had a fulminant, malignant course. A transient decrease in ICP elevation was achieved in 17 patients (26%) and a definitive control in 12 patients (18%), among them the 10 survivors in this series. In the authors experience once ICP is controlled, and unless haemodynamic instability compells action to the contrary, barbiturate should not be discontinued until a control CT scan shows complete disappearance of the mass effect.

Symptomatic subependymoma: report of four new cases studied with computed tomography and review of the literature

The authors describe four cases of subependymoma studied with computed tomography (CT) and review 18 previously reported cases in an attempt to define the most characteristic CT presentation of this rare, benign tumor. Subependymoma usually appears as an isodense, or even hypodense, intraventricular tumor on plain CT scan and shows minimal or no enhancement in postcontrast studies. Differential diagnosis between subependymoma and the more malignant true ependymoma is difficult, particularly when the tumor occurs in the posterior fossa. Recognition of subependymoma should prompt the surgeon to attempt radical tumor removal because it can be achieved without sacrificing contiguous tissue and carries a good prognosis.

Post-traumatic diffuse axonal brain injury. Analysis of 78 patients studied with computed tomography

A group of 78 severe head injury patients showing computerized tomography (CT) findings of the so-called "diffuse axonal injury" is analyzed. These patients represent 20% of the authors' series of severe head injury. Twenty-three patients showed small intraparenchymal haemorrhages in the CT scan study, 15 intraventricular haemorrhage and 40 patients had both intraparenchymal and intraventricular haemorrhages. Signs of brainstem haemorrhagic contusion were seen in 29 (38%) patients. Generalized brain swelling superimposed on the above findings was present in 75% of the cases. Raised intracranial pressure, which was found in 50% of the patients, correlated with the presence of ventriculocisternal collapse in the CT scan and an unfavourable outcome. Only 4 patients in this series made a good recovery, 13 developed a moderate disability, 11 a severe disability, 12 became vegetative and 38 (49%) died. The prognosis with this post-traumatic lesion is the worst in the authors' severe head injury series after excluding cases with subdural haematoma.

Intraventricular hemorrhage in severe head injury

A series of 30 patients suffering posttraumatic intraventricular hemorrhage (IVH) after closed head injury is reviewed. Clotted blood and a mixture of blood and cerebrospinal fluid could be distinguished by computerized tomography (CT). Posttraumatic IVH was associated with diffuse brain lesions in most cases; intracerebral lesions with contusion, and subdural hematomas coexisted with posttraumatic IVH in eight and four instances, respectively. In two more cases, no CT abnormality other than IVH was noted. All patients in this series were in deep coma at the time of CT examination, and only seven survived. The early clinical findings, the site of ventricular hematoma, and the final outcome are analyzed.

Intermittent exophthalmos studied with computerized tomography. Report of two cases

Two cases of intermittent exophthalmos are reported. In both instances, cerebral angiography and orbital venography failed to outline the lesion, which was clearly demonstrated with the aid of computerized tomography. An orbital varix was seen to be the cause of proptosis in one surgically verified case, whereas in the other this same diagnosis was suspected on the basis of the clinicoradiological findings. The etiology, clinical manifestations, and management of orbital varix are briefly discussed.

Observations on 82 patients with extradural hematoma. Comparison of results before and after the advent of computerized tomography

A consecutive, unselected series of 82 patients with epidural hematoma treated between 1973 and 1980 is presented. Forty-one patients were managed before the advent of computerized tomography (CT) and the other 41 after this neuroradiological method was available. Mortality and disability rates which were 29.2% and 31.7% during the pre-CT period decreased to 12.1% and 19.5%, respectively, with the aid of CT scanning. This technique allowed a more rapid and accurate diagnosis of the hematomas than angiography, and defined better the presence and the evolutional changes of the associated cerebral lesions. As a consequence, surgery has been more effectively planned and executed during the CT era.

Chronic adult hydrocephalus due to uncommon causes

The authors report on four unusual cases of chronic adult hydrocephalus extracted from a large personal series of patients with hydrocephalic dementia. A syndrome resembling that of normal pressure hydrocephalus was due to the following aetiologies in these patients: Paget's disease of the skull, unruptured cerebral arteriovenous malformation, colloid cyst of the third ventricle, and cerebromeningeal cysticercosis. All these patients exhibited disturbances in cerebrospinal fluid dynamics at the time of study, and were considerably improved by CSF shunting. The value of the continuous CSF pressure monitoring and the constant infusion test in selecting patients with chronic hydrocephalus for shunt therapy is emphasized.