scholarly journals Memoirs: The Collar-cells of Heterocœla

1895 ◽  
Vol s2-38 (149) ◽  
pp. 9-43
Author(s):  
GEORGE BIDDER
Keyword(s):  
Nuclear Membrane ◽  
The Other ◽  
Normal Life ◽  
Pathological Conditions ◽  
Other Hand ◽  
Paraffin Method ◽  
Method Show

THE collar-cells are in normal life short and barrel-shaped, with separated cylindrical collars, which are never united. In certain pathological conditions, probably connected with suffocation, they elongate very greatly, diminishing in the diameter of their upper part, or "collum;" and in some species, though not in Sycon compressum, the collars may then come into contact. In certain other pathological conditions the collar is lost, though apparently it can be regenerated. These metamorphoses appear unconnected with the ingestion of food, which also was not found to induce any migration of the collar-cells. On the other hand, migration seemed to occur under exceptionally unhealthy conditions. The collar is made up of (in Sycon compressum) about thirty parallel rods united by a film of some other substance. The flagellum is intimately connected with the nuclear membrane. There is an interstitial substance between the bodies of the cells. The area inside the collar appears to be provided with a sphincter membrane. Cells preserved and cut by the paraffin method show an average contraction of 5:4 linear in the best sections. In most preparations this contraction is uneven, producing Sollas's membrane and other fictitious appearances.

scholarly journals On Apogamy and the development of Sporangia upon fern prothalli

1898 ◽  
Vol 63 (389-400) ◽  
pp. 56-61
Keyword(s):  
Life History ◽  
Point Of View ◽  
The Other ◽  
Normal Life ◽  
Other Hand ◽  
General Importance ◽  
Two Generations ◽  
History Of ◽  
Alternation Of Generations

The two most important deviations from the normal life-history of ferns, apogamy and apospory, are of interest in themselves, but acquire a more general importance from the possibility that their study may throw light on the nature of alternation of generations in archegoniate plants. They have been considered from this point of view Pringsheim, and by those who, following him, regard the two generations as homologous with one another in the sense that the sporophyte arose by the gradual modification of individuals originally resemblin the sexual plant. Celakovsky and Bower, on the other hand, maintaint the view tha t the sporophyte, as an interpolated stage in the life-history arising by elaboration of the zygote, a few thallophytes.

scholarly journals Does the Interdependence between Oxidative Stress and Inflammation Explain the Antioxidant Paradox?

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Subrata Kumar Biswas
Keyword(s):  
Oxidative Stress ◽  
Chronic Diseases ◽  
Inflammatory Process ◽  
The Other ◽  
Present Review ◽  
Low Grade ◽  
Inflammatory Pathways ◽  
Pathological Conditions ◽  
Other Hand ◽  
And Oxidative Stress

Oxidative stress has been implicated in many chronic diseases. However, antioxidant trials are so far largely unsuccessful as a preventive or curative measure. Chronic low-grade inflammatory process, on the other hand, plays a central role in the pathogenesis of a number of chronic diseases. Oxidative stress and inflammation are closely related pathophysiological processes, one of which can be easily induced by another. Thus, both processes are simultaneously found in many pathological conditions. Therefore, the failure of antioxidant trials might result from failure to select appropriate agents that specifically target both inflammation and oxidative stress or failure to use both antioxidants and anti-inflammatory agents simultaneously or use of nonselective agents that block some of the oxidative and/or inflammatory pathways but exaggerate the others. To examine whether the interdependence between oxidative stress and inflammation can explain the antioxidant paradox we discussed in the present review the basic aspects of oxidative stress and inflammation and their relationship and dependence.

scholarly journals Comorbidity of diseases of the cardiovascular system and diseases of the digestive organs with changes in organs and tissue of the oral cavity

2021 ◽  
Vol 2 (3) ◽  
pp. 6-17
Author(s):  
Dmitry I. Trukhan ◽  
◽  
Larisa Yu. Trukhan ◽  
Darya S. Ivanova ◽  
◽  
...  
Keyword(s):  
Oral Cavity ◽  
Cardiovascular System ◽  
Digestive System ◽  
The Other ◽  
Adequate Treatment ◽  
Digestive Organs ◽  
Pathological Conditions ◽  
Other Hand ◽  
Clinical Cases

Currently, in most clinical cases, the patient has a concomitant or combined pathology described by the terms "polymorbidity" (in the absence of a pathogenetic relationship) and "comorbidity" (in the presence of a pathogenetic relationship) between various diseases and pathological conditions. In the system of relationships between an internist and physicians of other specialties, the least studied aspects of their clinical interaction with a dentist. At the same time, often the reason for a patient's visit to the dentist is the presence of somatic pathology, and for the most part, not completely healthy patients come to the dentist's appointment, whose problems are limited to the oral cavity. On the other hand, the presence of certain changes in organs and tissues of the oral cavity and the advice of a dentist can help the internist in the diagnosis and adequate treatment of the patient. The first part of the presented review examines possible changes in the organs and tissues of the oral cavity in patients with diseases of the cardiovascular system and diseases of the digestive system. The second part of the review is devoted to the analysis of the possible effect on the organs and tissues of the oral cavity of drugs used to treat cardiovascular and gastroenterological diseases.

scholarly journals Mitochondria, pattern recognition receptors and autophagy under physiological and pathological conditions, including viral infections

2021 ◽  
Author(s):  
Paulina Niedźwiedzka-Rystwej ◽  
Dominika Bębnowska ◽  
Roman Kołacz ◽  
Wiesław Deptuła
Keyword(s):  
Pattern Recognition ◽  
Viral Infections ◽  
Apoptotic Cell ◽  
Pattern Recognition Receptors ◽  
The Body ◽  
The Other ◽  
Cellular Processes ◽  
Pathological Conditions ◽  
Other Hand

Research on the health of mammals invariably shows how dynamic immunology is and how the role of many elements and immune processes of the macroorganism, developed in the process of evolution in protecting against threats, including infections, is changing. Among these elements conditioning the homeostasis of the macroorganism are mitochondria, PRR receptors (pattern recognition receptors) and the phenomenon of autophagy. In the context of physiological and pathological states in the body, mitochondria perform various functions. The primary function of these organelles is to produce energy in the cell, but on the other hand, they are heavily involved in various cellular processes, including ROS production and calcium homeostasis. They are largely involved in the activation of immune mechanisms during infectious and non-infectious conditions through mtDNA and the mitochondrial MAVS protein. Mitochondrial involvement has been also determined in PRR-related mechanisms as mtDNA has the ability to directly stimulate TLRs. On the other hand, mitochondria are also associated with apoptotic cell death and autophagy.

scholarly journals THE ROLE OF HYPOXIA IN THE DEVELOPMENT OF SOME PATHOLOGICAL CONDITIONS AND MALIGNANT TUMORS

2021 ◽  
Vol 67 (2) ◽  
pp. 53-66
Author(s):  
N.O. Bogdanova ◽  
◽  
N.H. Pogorela ◽  
E.A. Lukyanetz ◽  
◽  
...  
Keyword(s):  
Oxygen Tension ◽  
Malignant Tumors ◽  
The Body ◽  
The Other ◽  
Internal Factors ◽  
Pathological Conditions ◽  
Other Hand ◽  
Physiological Value

Hypoxia, which could be defined as the level of oxygen tension in the body that is below the normal physiological value, is a process that is often observed in several diseases and occurs in most malignant tumors. On the other hand, in hypoxia several pathological conditions could occur, which could be caused by external and internal factors. During carcinogenesis, hypoxia may promote metastasis and an unfavorable prognosis. When infected with COVID-19, there is a «silent hypoxia», which could asymptomatically destroy the body. The review is devoted to hypoxia’s role in the development of some pathological conditions and malignant tumors.

scholarly journals Lecture of the cycle of specialization in reflexology «Using reflexotherapy as a part of integrated therapeutic measures in cosmetology»

2017 ◽  
pp. 28-33
Author(s):  
G. Chupryna ◽  
G. Chupryna ◽  
T. Parnikoza ◽  
N. Svyrydova ◽  
T. Cherednichenko
Keyword(s):  
Side Effects ◽  
The Other ◽  
Lecture Material ◽  
Pathological Conditions ◽  
Other Hand ◽  
Wide Range ◽  
Therapeutic Measures

Improvement of the course on the topic "Specialization on reflexology" of the lecture material on the theme "Use of reflexotherapy as part of complex therapeutic measures in cosmetology" has helped to reduce the pharmacological burden on patients and minimize the possibility of development of complications and side effects of pharmacotherapy. On the other hand, application in the structure of therapeutic measures of acupuncture will undoubtedly increase the effectiveness of therapy of a fairly wide range of pathological conditions in dermatology.

scholarly journals The Infrared Spectra of Synthesized Amorphous Silicates with Compositions of Olivine and Pyroxene

1991 ◽  
Vol 126 ◽  
pp. 95-98
Author(s):  
Chiyoe Koike ◽  
Akira Tsuchiyama
Keyword(s):  
Infrared Spectra ◽  
The Other ◽  
Symbiotic Stars ◽  
Peak Wavelength ◽  
Evaporation Method ◽  
Other Hand ◽  
Method Show

AbstractAmorphous olivines synthesized by evaporation method show two very broad bands at 10-11 μm and 17.5-19 μm, which resemble the spectra of symbiotic stars. On the other hand, amorphous pyroxenes produced by the same method show two broad bands at 9.5-10.3 μ and 20-22 μ which are narrower than that of amorphous olivine. The features of amorphous olivine were easily altered by heating or hydration, and the peak wavelength of 18 μm band was easily shifted to longer wavelengths.

A teratological pygidium of the Upper Cambrian trilobite Eugonocare (Pseudeugonocare) bispinatum from the Machari Formation, Korea

2001 ◽  
Vol 75 (1) ◽  
pp. 216-218 ◽  
Author(s):  
Jeong Gu Lee ◽  
Duck K. Choi ◽  
Brian R. Pratt
Keyword(s):  
The Other ◽  
Parasitic Infestation ◽  
First Report ◽  
Upper Cambrian ◽  
Pathological Conditions ◽  
Other Hand ◽  
Predatory Attack ◽  
Cambrian Trilobite ◽  
Machari Formation ◽  
Number Of Segments

Abundant examples of exoskeletal abnormalities have been known in various trilobites since Portlock's (1843) first report on a teratological pygidium of Phillipsia ornata (cf. Babcock, 2000). Owen (1985) and Babcock (1993) recognized three types of trilobite malformations: healed injuries, teratological conditions, and pathological conditions. It is not always easy, however, to distinguish between the various types of malformations, especially in case of teratological or pathological conditions. In general, healed injuries are considered to have resulted from trauma during molting (Walcott, 1883; Whittington, 1956; Henningsmoen, 1975; Snajdr, 1981; Owen, 1983; Ramsköld, 1984) or wounds by predatory attack (Ludvigsen, 1977; Rudkin, 1979; Ŝnajdr, 1979, 1981; Owen, 1985; Conway Morris and Jenkins, 1985; Babcock, 1993; Pratt, 1998). Many healed injuries are indicated by broken spine stumps, indented and cicatrized edges of exoskeletons, and callused or regenerated exoskeleton around the broken surface (Ŝnajdr, 1981; Owen, 1983; Babcock, 1993). Teratological conditions are represented primarily by the irregular development of glabellar lobes, cephalic borders, and pygidial border spines, and anomalous number of segments on the thorax and pygidium. For example, Owen (1980) described a teratological cranidium of Calyptaulax norvegicus with two additional lateral glabellar lobes between the l p and 2p lobes. On the other hand, pathological conditions are marked by gall-like swellings and vermiform borings on exoskeletons that are thought to have been caused by diseases or parasitic infestation (Lochman, 1941; Ŝnajdr, 1978; Conway Morris, 1981; Owen, 1985).

A study of cometary eruptions through OH radio-lines

1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró
Keyword(s):  
Short Duration ◽  
Growth Curves ◽  
The Other ◽  
Initial Mass ◽  
Radio Lines ◽  
Other Hand ◽  
Sudden Rise

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.

Closing the GAP—A 5Å Scanning Microscope

1969 ◽  
Vol 27 ◽  
pp. 6-7
Author(s):  
A. V. Crewe
Keyword(s):  
Normal Form ◽  
The Other ◽  
Resolving Power ◽  
Scanning Microscope ◽  
Conventional Microscope ◽  
Other Hand ◽  
Closing The Gap ◽  
Thermal Sources ◽  
Better Than ◽  
Transmission Microscope

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.

Sign in / Sign up

Export Citation Format

Share Document