Possible superconductivity at room temperature

Antonowicz, K.

doi:10.1038/247358a0

Cited by 64 publications

(54 citation statements)

References 6 publications

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“…The recorded profile illustrated in Fig. 3 is in agreement with that reported for many lysosomal enzymes, including acid-P-galactosidase, in developing human fetal jejunum [29]. Few data are available regarding the modulators involved in the development of acid-b-galactosidase activity in rats [30] and none for human.…”

Section: Discussionsupporting

confidence: 76%

The expression of lactase enzymatic activity and mRNA in human fetal jejunum Effect of organ culture and of treatment with hydrocortisone

et al. 1992

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Very sensitive procedures were developed for the parullel determination of intestinal lactase (LPH) activity and the cognate mRNA. Between 14 and 20 weeks of gestation, lactase activity is low and varies only slightly; at 37 weeks, a relatively high level of activity is observed. The amounts of LPH mRNA correlates with the enzymatic activity (r = 0.64). Culture of fetal jejunal explants for 5 days induces by itself a 2.fold increase in LPI-I mRNA, without any significant change in lactase enzymatic activity. This increase may reflect the loss ofa negative transcriptional regulation opcldtive in vivo, and suggests an additional post-transcriptional regulatory componenl, The addition of hydrocortisone (50 n&/ml) during culture induces a doubling of lactuse activity without variation in LHP mRNA, indicating a post-transcriptional modulation by hydrocortisone, The intestinal lysosomal ucid &guluctosidase activity wus shown to bc unaffected by hydrocortisone treatment. This observation clearly illustrates that the two intestinal P~galactosidascs are regulated differently. Our results suggests a complex developmental regulation of human intestinal lactase and [hut the perinatal increase in lactase activity could be modulated at a post-transcriptional level by hydrocortisone.

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Section: Discussionsupporting

confidence: 76%

The expression of lactase enzymatic activity and mRNA in human fetal jejunum Effect of organ culture and of treatment with hydrocortisone

et al. 1992

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“…We are not aware of any published report showing similar results as those in [1,2]. In what follows we review some magnetization results obtained in water and n-heptane treated highquality graphite powders that suggest that granular superconductivity might be indeed possible in the powders, very probably at certain interfaces created after the corresponding treatments [7,8].…”

Section: First Hints For Room Temperature Superconductivity In Dismentioning

confidence: 86%

“…The field dependence of this "critical current" I c follows the field dependence given by the Josephson critical current equation I c = |I 0 sin(x)/x+I 1 | whereas x ∝ H, H the applied field and I 1 a fieldindependent constant background current. This constant as well as the field ∆H at which I c shows the first minimum are sample dependent, the last between 0.1 Oe < ∆H < 1 Oe [1].…”

Section: First Hints For Room Temperature Superconductivity In Dismentioning

confidence: 99%

“…In the year 1974 Kazimierz Antonowicz published studies [1] on current-voltage I − V characteristics curves of annealed carbon powder contacted between two Al electrodes. He recognized a kind of "critical current" I c from the I − V curves and measured the influence of low amplitude applied magnetic fields on I c .…”

Section: First Hints For Room Temperature Superconductivity In Dismentioning

confidence: 99%

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Evidence for room temperature superconductivity at graphite interfaces

Esquinazi

Precker

Stiller

et al. 2017

Quantum Stud.: Math. Found.

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In the last 43 years several hints were reported suggesting the existence of granular superconductivity above room temperature in different graphite-based systems. In this paper some of the results are reviewed, giving special attention to those obtained in water and n-heptane treated graphite powders, commercial and natural bulk graphite samples with different characteristics as well as transmission electron microscope (TEM) lamellae. The overall results indicate that superconducting regions exist and are localized at certain internal interfaces of the graphite structure. The existence of the rhombohedral graphite phase in all samples with superconducting-like properties suggests its interfaces with the Bernal phase as a possible origin for the high-temperature superconductivity, as theoretical calculations predict. High precision electrical resistance and magnetization measurements were used to identify a transition at Tc > ∼ 350 K. To check for the existence of true zero resistance paths in the samples we used local magnetic measurements, which results support the existence of superconducting regions at such high temperatures.

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“…Superconductivity with relatively high T c s was observed in carbon materials: at T c = 35 K in graphite-sulfur composites [1] and close to room temperature (627) in higly oriented pyrolytic graphite (HOPG) [2], carbon nanotubes [3], and amorphous carbon [4]. In modified graphite, superconductivity occurs in a small sample fraction or is thermally unstable [1,5].…”

Section: Introductionmentioning

confidence: 99%

Superconductivity of Carbon Materials - Unstable Phases

Kempiński

2004

Acta Phys. Pol. A

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Different intercalated carbon systems: K x C 60 , Rb x C 60 as well as highly oriented pyrolytic graphite + potassium with unstable structural and superconducting behavior were investigated with the EPR and magnetically modulated microwave absorption techniques. Three characteristic, well--separated EPR signals were observed for A x C 60 (A = K or Rb) systems at the early stages of doping process. We ascribed these signals to C = (18.5 ± 0.5) K (final, stable) were distinctly separated for K x C 60 system. For C 60 intercalated by rubidium a similar evolution of EPR spectrum is observed. Prior to well-defined superconducting Rb 3 C 60 phase was created, strong instabilities of the magnetically modulated microwave absorption signal were observed at the narrow part of the doping process. For potassium intercalated highly oriented pyrolytic graphite, EPR oscillations below 100 K were observed as well as Josephson hysteresis loops were registered at 5 K.

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Possible superconductivity at room temperature

Cited by 64 publications

References 6 publications

The expression of lactase enzymatic activity and mRNA in human fetal jejunum Effect of organ culture and of treatment with hydrocortisone

The expression of lactase enzymatic activity and mRNA in human fetal jejunum Effect of organ culture and of treatment with hydrocortisone

Evidence for room temperature superconductivity at graphite interfaces

Superconductivity of Carbon Materials - Unstable Phases

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